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.
Your mother-in-law has no right to interfere in the marital life of her son unless she wants to reconcile [between the two of you]. If she really provokes you and says hurtful words to you, then she is wrongful in doing that. However, being patient and repelling a bad deed with a good deed is a characteristic of the people of virtue. Allaah says (what means): {And not equal are the good deed and the bad. Repel [evil] by that [deed] which is better; and there upon, the one whom between you and him is enmity [will become] as though he was a devoted friend.}[Quran 41:34]
Ibn Katheer said (about the interpretation of the above verse) in his Tafseer (interpretation of the Quran): “That is to say that if you do good to someone who mistreats you, then this good that you do will lead him to have a good attitude towards you, like you, and be compassionate with you; until he becomes like an intimate friend to you, who is sympathetic and kind to you.”
For more benefit on the virtue of patience, please refer to Fatwa 83577.
However, patience does not mean that the wife should not request her rights over her husband. For more benefit on how a wife could solve the interference of her in-laws in her marital life, please refer to Fatwa 181485.
On the other hand, the son [your husband] should be wise; he should give his mother her right and give his wife her right so as not to wrong either one of them at the expense of the other.
In case a wife stipulates a condition at the time of concluding the marriage contract that does not contradict the purpose of the contract and he accepted it, then he is obliged to fulfill it as clarified in Fataawa 131714 and 157809. However, the mere fact that the wife was studying at the time of concluding the marriage contract does not make it a condition that she continues her studies.
As for your husband’s obedience to his mother, it is not an absolute obligation; rather, the jurists stated that a child is to obey his mother in what involves benefit for the mother and no harm for the child, as clarified in 84942.
Finally, we advise you to be wise and cautious so that the problem does not aggravate so as to cause dissension and separation. Also, you should pray to Allaah to set the matter right and grant you stability.
Allaah Knows best.