All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Divorce is permissible especially when there is a need for it, and it is disliked if it is without a need. A wife is obliged to reside where her husband resides and she is not permitted to travel without his permission. If your wife had insisted to travel without your consent, then she is disobedient, however, you should have followed the steps determined by the Islamic Law in disciplining a disobedient wife before divorcing her.
For more benefit on the steps to follow when dealing with a disobedient wife, please refer to Fatwa 85402. Nonetheless, you are not wrong in divorcing her.
Moreover, it should be noted that adoption is forbidden, but if it happens, it does not mean that there is any impediment for marriage between this adopted child and the woman who adopted him. Indeed, these two children as well as your wife’s ex-husband are not Mahrams to her. Therefore, it is not permissible for her to reside with them or be in seclusion with any one of them.
For more benefit, please refer to Fataawa 91409, 84422 and 82371.
Allaah Knows best.