What ginny said. And if hubby gets a job he will have to support his children from a previous marriage. Your sister needs to understand that THEY deserve support. If he wont' support them he sure as heck won't be supporting the new baby. Deadbeats don't change.
Parents should remember 3 things: Love your kids more than you hate your ex; when you have children the relationship with the other parent is until death; your children determine what type of nursing home you end up in.
Nothing stated by me should be taken as giving you legal advice or forming an attorney/client relationship.
Attorney-GAL in Ohio.
I've removed the knife from my back, polished it, and will one day return it -- long after you think I have forgotten.