How do you know she is using her relationship with her boyfriend to validate herself?

I wonder if she ever shared with you how is their relationship really working on the inside, do you have evidence that she is insecure rather than just being content? Otherwise she might be just very happy in her relationship and she might be the type to show it, some people are more demonstrative about their relationships and some are more private. Some people really like to scream to the world about their happiness re child and a good partner. It’s not abnormal either way. Just how some people are. Sure it could get annoying if they stop you on the street and want to blab about their family or force you to look at pics. Sure I could see it’s annoying. Not necessarily abnormal, but if she just posts on social media and clings to her family at parties it’s pretty easy to ignore.

How much did she share with you about her relationship with her boyfriend? Is it possible they simply are having a good life and she likes to share? If you observed him being abusive but then she posted loving pictures, it would be concerning. Otherwise her oversharing isn’t abnormal, her posting or tagging or otherwise sharing about her partner. Not my style but I don’t think it’s wrong of others to do it