Gerda is right. If you get the custody, great. Better for the kids. You can always let her see them if she is being appropriate and refraining from abuse toward you or others. The only difference will be that you can control the terms (and keep them in their school, get the child support you need, etc.). I think sometimes when we worry too much about them, it is really a fear of letting go. Let her go all the way. You don't know what the future holds, but you don't want her to take you and the kids with her.