Is it permissible to wear a hijab sewn by one's mother based on a borrowed hijab from a neighbor who mocks religion, and should this neighbor be shunned?

Mocking the religion is major disbelief that expels one from the fold of Islam, but a specific individual is not judged to be a disbeliever until the conditions are met and the impediments are removed. As for borrowing from a disbeliever, it is permissible, for the Prophet, peace and blessings be upon him, borrowed armor from Safwan ibn Umayya. As for shunning a neighbor, it depends on the legitimate Islamic interest: if there is benefit in shunning her, then she should be shunned; otherwise, communication should be maintained while continuing to advise her.