How to deal with BF's jealous mom?

BF and I have been together for a few years now and know each others families very well. Recently I've noticed his mom is a lot more vocal about how she sees her son less (because we are living our independent lives together). She is now constantly teasing me in little ways that seem like a product of her feelings toward me. I really like her and we get along well but I feel a little on edge around her because I want her to have a positive view of me. Yes I've talked to my BF about it and he assures me his parents love me and always ask how I'm doing (plus they reach out to me directly). We see them 4-5 times a year for about 2-3 days at a time. Am I not doing enough or how can I re-frame my thinking to not feel anxious about this.