Not weird at all. My T isn't a mother, but she's very close to her neices and nephews. On my birthday, she said to me "I'm going to sing you happy birthday like I sing to my neices and nephews." I felt so special and touched.

We are in quite a close relationship: not the same as family, but therapeutic family, where she's in the 'good enough' mother role, and I do have similar feelings to yours sometimes about it. It's lovely to be cared about in a maternal way. I know the difference between an actual birth mother and my therapist, and I appreciate it for what it is.