To skip or not to skip

Amelie is brilliant. :) I say this because her new school says she tested in the top two (let's face it, she's #1) of her school. Now they want to move her up to the 4 & 5 year old class where they learn actual reading and math. Academically I know she can handle this, she is reading spontaneously all over the place these days. "C-ah-m-p-a-c-t - what's "compact", mama?" on our parking spot, for instance. I just worry about her being the baby in the class, I want her to make friends. It took a long time at Montessori and when she finally had a "best buddy", they closed. We're taking the chance, she would be bored silly learning the alphabet. We'll see how it goes.