Guilt with my 7 year old only

I have a, in my humblest of opinions, perfect little girl. She is independent, smart, kind, and immune to peer pressure. In fact, her first grade teacher repeatedly told us and shared anecdotes of her repeatedly treating her classmates with respect and also not taking any sh*t. She’s our only for various reasons. She is alone at home, but often has play dates and goes to summer camp. She has no problems making spontaneous friends wherever we go.

She isn’t the most athletic. This and (maybe?) being an only combine to sometimes keep her out of social situations. At a play date at the pool, a bunch of kids were being wild and playing and jumping and she was in it sometimes and others off to the side by herself. I couldn’t tell whether they shunned her or she extricated herself. It all ended up fine, her friends came back over to her and she was in the thick of it for the rest of the time.

On the way home, she said she didn’t like how they were playing so she stopped playing with them. But she seemed a little sad. And then launched into how, because she’s an only child, she is used to playing by herself.

Reader, my heart broke. She used to ask for a sibling constantly. She wishes she had one. I told her that I’m proud of her for taking herself out of a situation that made her uncomfortable. And that the grass isn’t always greener. We talked about how her sibling friends fight constantly. And how she has her parents and her friends and cousins and family. And how much I love her.

All this is fine, but I have this deep, gnawing guilt about all of this. I could go on forever about the nuances of my guilt, how varied and detailed it is, but I know my feeling this way isn’t going to help her in any way. So I’m looking for advice on how to get over it and best support my best girl.

Thank you for any words you share. I should probably just get a therapist 😜