Likely a model "Barbara". First appears in the family photo archive on my mother's wrist in the Spring of 1947. She was married to my father in December 1946; my 3 siblings and I believe this was a wedding gift for her, though none of us remember her mentioning this detail. He died in 1994, and she died in 2009. Additional photos show this was her daily wear watch from 1947 until 1977. It does not appear on her wrist after 1977. The watch was likely purchased in either Philadelphia or Hartford (where they were married). She and my father lived most of their lives in Philadelphia PA and Pittsburgh PA. I have tried my best to photograph / scan jewelers marks - it required different lighting for each of the three marks to yield somewhat legible images.
Lovely heirloom and thanks for sharing the story to the watch. Yes it is a Barbara like this one https://www.mybulova.com/watches/1945-barbara-13611
1946 Bulova Barbara
1946 Bulova Barbara is a good match. I think the service marks, which really don't translate very well as every watchmaker used her/his own code, are a testament to how much the watch meant to your mother in that she kept it well serviced. Congrats on a special keepsake from her.
PS - if you plan to continue wearing it (I sure hope you do) I recommend still another service to keep it running strong.