What is the ruling of Islamic law concerning dealing with a mother who seeks to separate her son and his wife through sorcery and falsely swears upon the Qur'an, while it is impossible to separate from her in residence?

If the mother resorts to sorcerers, she is committing a grave evil. It is obligatory to advise her gently and kindly. If you do not have clear evidence that she is trying to cause separation between you and your wife, then the presumption is that she is innocent. You both must fortify yourselves with legal (Shar’i) remembrances and invocations. If your mother desires for you to stay with her, then satisfying her is more proper. However, you have the right to a private residence for your wife if you wish, while still committing to visit and care for your mother.