I don't think there's a problem with teachers sharing aspects of their lives with kids, especially once they get to 10+, within reason obviously. I think the days of the "stern, distant school teacher" who is only there for academics & discipline is a bit outdated really.
It can go the other way of course - my daughter had a newly qualified teacher last year who was "everyone's pal" - the kids all thought he was amazing, best teacher ever, so much fun... but frankly as a TEACHER he was absolute pish

. I went to her parents evening and straight afterwards texted my wife "FFS he has no idea what he's doing haha". I'm not convinced she learned anything at all last year, and some of what he was teaching was straight up INCORRECT

...
Anyway, off topic there a bit, but yeah I think it would be quite nice for a teacher to share wedding pics with the kids if they're interested.
Does anyone else remember the drama and chaos that would ensue at primary school when a teacher got married and changed their name?

. "Can you take this along to Mrs White?" "...who??? That's Ms Smith! WHAT IS HAPPENING"