Background:
BM has had full custody of SS since they went to court when SS was 4. He is now 13. Dh has had regular visitations since then and has been paying child support every month ( he has voluntarily increased child support through the years as his income increased). Bm is very unstable and has lost custody of her younger daughter(not DH's) to the paternal grandmother. Anyways we live 9 hrs away and so we get him for extended weeks in the summer. Anyways a few years ago she offered for Ss to come live with us permanently and it was hard and she ended up yanking him back. Now she is offering for him to come live with us again.
My question is what should be the process when switching custody? What kind of requests should we ask of BM so takig him back would not be an option since it would be very disruptive to everyone.
Thanks in advance