step parent adoption/child support

[azhuskrs]

What is the name of your state? Arizona
I am divorced of seven years with one son in common. I currently share joint custody with my "X" on our eleven year old son. Neither currently pay child support for this one son.
My "X" had full custody of two boys from a prior marriage that she supported. I never adopted either of these boys. She makes 90K/year and I make 70K/year. AZ child support calcuation tables showed it to be a wash.
My "X" has now remarried. Married to a man who has full custody of four girls. To my knowledge, she has not adopted any of the four girls he has custody of.
Now one of the two boys of the "X" has turned 18 years of age and is now longer figured into the equation as far as child support goes in AZ. Based on the fact that the "X" can only claim to support one boy when calculating child support in AZ, I should be entilted to child support from my "X", now.
Questions I have are as follows:
1) Should I wait until next summer when her other son turns 18 years of age to collect any child support that the "X" might owe me?
2) Could the "X" possibly have adopted these four girls or any combination thereof that her current husband has custody of to where I could or would be obligated to pay her child support?
3) Is it possible for the "X" to come after me for child support should she adopt any of these four girls?
4) Would the child support calulations table be different when figuring child support for my one son should this be the case? Would it be her income and his income totals figured into the child support against my sole income?
5) Is it public record to see if she has in fact adopted these girls already? What would the web site be? How can I find out?