Opinions please....WWYD

We recently moved to Florida and the age cutoff for kindergarten is in Sept.

In her NY district it was 12/1. Her bday is 11/29 and when it was time for her to start k and we had the option to hold her back or let her start- we let her start because academically she was more than ready and she has done really well in both k and 1st, inspite of being so much younger than the other kids- some a full yr.
Now she is ready to start 2nd grade in florida, where theoretically some kids could be almost a year and a half older due to the sept cut off.

Academically she will be fine but I am concerned about her socially, a little now but mostly as she gets older.

She would NOT be happy if we told her she had to go back to first grade and I really don't want to do that.
Thoughts?
School starts monday, I just realized the cut off date this morning and it was not brought up at the school at all when I registered her or met her teacher.
Thanks for reading- i'm so confused!

Opinions please....WWYD

If you think she will be bored in 1st grade, I would send her to 2nd. I would hate to see her lose interest in or be bored with school at such a young age.