In custody situations it is really best to have an attorney because of the emotional issues involved. I go pro se when it is a matter if child support unpaid or a change in support, or when CSE sticks their nose under the tent. I, being a disabled vet, also handled all of my VA appeals since I don’t trust anyone who works at any VA office as far as I can throw them. How old are your kids?
If they do want to come and live with you, use a hidden tape deck in your home and don’t bait them up, just get them to start talking and you will be surprised how much incriminating stuff they will tell you about her, especially if she goes off and leaves them alone, etc. If you have good ins. where you work, then try to take them to the counselor or psychologist regularly. You will be surprised what the kids will tell them.
You can do much of this prep without an attorney. Then when you think you have your BB’s all stacked go to an attorney and present your case before you retain him. Additionally, you need to carefully pick an attorney because, as you know, many just want to run the bill up. If you wait too long the courts will say that the kids have developed a “Long Standing Relationship” with their mother and won’t give you the time of day, but if the divorce is less than 5-7 years old you may stand a fair chance. Believe me, I was shocked that I won custody, but I followed the recomendations which I have posted.