Sayyidah Asma' bint Abi Bakr (may Allah be pleased with her) said: My mother came to me while she was a polytheist, so I asked the Messenger of Allah (peace and blessings be upon him) for permission to maintain ties with her, and he (peace and blessings be upon him) said: "Maintain ties with her."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20712