I am very curious to what this means?

I am really not here to offend ANYONE. I’m very non judgement I am just curious so I can understand others. A friend from college uses a LGBT flag near her profile on Instagram next to her name at birth but also, she has used a DIFFERENT name to her birth name (which appears to be of feminine nature) with “she/her” next to it. Since I was in college she was always identified as female. What does this mean?

I’m not bothered it doesn’t change anything. I’m just curious as I am seeing it more in emails with people at work but don’t know how to ask them. I just want to understand what it means. So I’m not oblivious

Thanks for your understanding.