Praise be to Allaah.
The great rights of the mother are well known, and it is obligatory to honour her and treat her well, but if the matter is as described, and the woman asked about will be harmed by living with her mother, and she wants to live in her own apartment, there is no sin on her for that, if the place is safe and no bad consequences will result from her living alone, so long as she fulfils her duties towards her mother by honouring her, treating her kindly and serving her if she needs that, or helping her financially.
The Standing Committee for Issuing Fatwas was asked about someone who wanted to live alone, away from his parents, because he could not feel at ease when living with his family.
They replied: If the situation is as described and you cannot feel at ease living in your parents’ house, there is no sin on you if you live away from your family in a separate house, in order to find peace, but you must also fulfil your duties towards your parents and uphold the ties of kinship, not sever them. End quote from Fataawa al-Lajnah al-Daa’imah (25/169).And Allaah knows best.