Here's what I think...
My boyfriend paid all the bills when he left his now ex-wife. They did not file legal separation until six months after he left. However, he put money in their joint checking account and he kept the bank deposit slips in order for her to pay the bills. Now, before I go on, anything you pay before filing legal separation does not count. It only helped my boyfriend by not paying alimony. Here's how. The lawyers (his included) kept saying property matters were settled and the joint bank account was property. Yet it wasn't property. It's an asset. He could show that he put money in the joint checking account by having the deposit slips and that she would need to split the account. No matter if she paid the bills with it or not. They dropped the alimony because she would not get life time support. They figured she would get only two years of alimony around $150.00 per month. She would have a tax liability on the alimony and the difference in the amount he deposited and the amount of alimony she would get would cost her more in the long run.
If you do plan to get a divorce, I would come to terms with my soon to be ex before you file. Settle how property is to be split or sold, money division, child support, etc. Because if you don't end up with an agreement before you see a lawyer, you'll both rack up large attorney fees. The attorney's will end up with the money and you'll both end up with nothing. If you can't settle before filing, go to mediation together. But for God's sake, never sign an "agreed 14 day waiver" when it comes to property until you have what you think is fair. Never tell your attorney that you want this and that for now. Tell him everything you want at your first meeting. Don't forget your rental property, who will live in the house, if the house is to be sold, how the money is to be split, contents of household goods, who is to pay what bills, guardianship of the children, etc. Take all your bills with you when you meet your attorney for the first time. Also take your pay stub and tell him what your wifes take home pay is. Make sure he spells out when filing who is to pay certain bills. Make sure your name is off all joint credit accounts too if your just a user of the credit account. I'd do this now.
My boyfriends ex contested the divorce when he filed. She asked for child support and payment for all the bills. The child support office didn't notify him nor did his lawyer until two months after the child support and order for payment of all the bills took effect. So he ended up being two months behind and she filed contempt charges just before their first hearing with the attorneys was scheduled. Even though he deposited money into the joint checking account for those two months for payment of the bills. It was deemed a gift. He only had the clothes on his back more or less. They forced him to sign the "agreed 14 day waiver" at that hearing which settled all property. They told him if he didn't sign it, then he would be held in contempt and go to jail for non-payment. So, she ended up with all the property, the proceeds from the sale of their land etc. He was screwed. Then because she didn't want to take any of the bills, they forced them into bankruptcy to settle the matter and he ended up paying more in child support. Never believe that you'll go to jail on the first contempt charge. His attorney even admitted that it would take 5 or 6 contempt charges before the judge would consider jail. His attorney told him this after he signed the "agreed 14 day waiver." They bullied him into signing. Remember, her lawyer and even your own attorney want to settle matters quickly. No matter who gets hurt or screwed. The judge wants the divorce off their docket and the attorneys know it and the attorneys don't want to piss off the judge.
Make sure you have a good attorney that will go to bat for you. Check out complaints with the BBB, the Bar Association etc. before you decide on an attorney. The yellow pages is not a good place to find an attorney. Call the Bar Association. I also think it's best to find an attorney in the next county who is license to practice in both counties. He is more likely to work in his own county than yours and isn't friends with all the attorneys in the county where you reside. This way you have an edge instead of having an attorney in the same county who knows and are friends with each other. I can tell you stories that I overheard while sitting in the hallway between attorneys. They are friends and don't give a damn about either of you. They'll settle more in favor with your wife than you. They owe each other favors. Tell your attorney what you expect from him and write it down in the contract with your attorney. Don't take his word that he will keep in touch with you. He'll fail to send you copied of your orders, return your phone calls, etc. Spell it all out in the contract with your attorney. If your attorney doesn't agree to put your terms into the contact, then you know it's time to find another attorney.
I should also note, most courts are online now and you can follow your case online.
Remember that everytime you speak with your attorney, he is billing you. This is why I said it's best for you and your wife to agree on matters prior to filing for a divorce. So both of you end up with the money in your pockets. My boyfriend ended up paying $6,500 + for his attorney. I'm sure his ex paid about the same. The divorce took a year and a half because she kept wanting more and there was nothing to get and they had to wait until the bankruptcy was completed before they would grant the divorce.
Please know that most divorce matters are settled with the attorneys before you even see the judge. All the judge does is see that all matters were handled and hits the gavel and your divorced.
Please also note, my boyfriend filed first. The day he filed he had an opportunity to file for guardianship of his children and pick them up that day. But my boyfriend said, "No, I want my kids to decide where they want to live." Well, when his ex filed and contested the divorce, she filed for guardianship of the kids. Lets just put it this way, who ever files for guardianship first ends up with the kids. Don't believe children have a right to decide where they want to live. The judge may listen, but in most cases they don't even bother.
So, my advice is to stop giving her a monthly check. Deposit enough money into the joint checking account to cover the bills you agreed to pay until you file for divorce. Stop depositing money into the joint checking account once you file and pay the bills direct. Remember, anything you give to her before filing is a gift. Once you've filed and are ordered to pay certain bills, do not give her any money. If you do, it's considered a gift. Setup your own checking account now. That way you can start paying the bills direct once you've filed and are ordered to pay certain bills.
I do have one question for you. Who is paying the mortgage and taxes on the rental property? If she is getting half the rental income, then she should pay half the mortgage and property taxes. This way it shows your both responsible for the property and it won't look like your giving her extra income. If she is just intercepting the money from her sister, then you should take her sister to court for non-payment of rent. How is the lease written? Send you wife a copy of the mortgage and tax bill each month and write what her half is and either pay you or the mortgage company direct. I'd opt for her to pay the mortgage company direct because then she'll know if she defaults, the property will go into foreclosure. Tell her that your only paying half the mortgage and what will result if she doesn't pay. I'm sure she won't want to lose the income.
Good luck!