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.
There is a difference of opinion among the scholars on the ruling of wearing a wig, some permitted it and some prohibited it. The view we adopt here in Islamweb is that wearing a wig is permissible with the conditions which we mentioned in Fatwa 90912, especially if wearing it is in order to cover a malformation, because removing a malformation is permissible, and it is for this reason that the Prophet allowed the person whose nose is cut to replace it with a golden nose.
Based on the above-referred Fatwa, it is permissible for you to make a wig for your mother to wear.
For more benefit, please refer to Fatwa 87229.