Mention to her what your friends are saying and how it makes you feel. Hopefully, she will understand and will tone down the chanting while your friends are around. If she doesn't, don't invite your friends home and she will have to deal with the fact that her new-found spirituality is losing her time with her daughter. Dear Pastor Paul, I'm dating a Jewish guy, but I'm not Jewish. My boyfriend's parents are constantly telling him that he should only be dating Jewish girls, because he has to marry one.
All relationships require sensitivity and commitment.
Interfaith relationships require extra sensitivity and commitment. You, my Kansas friend, are in an interfaith relationship. If the answer is no, then cool off, hang out, and just be friends. If the answer is yes, then start by asking him about his religious beliefs, and share your own with him. Explore what you really feel about interfaith relationship and ask him what he feels.