Is 122 a good IQ for a 13-year-old girl?

hmmmm.. It seems to me that you are very bright and can make it in the real world.

Age is irrelevant. IQ tests take age into account so that ideally your IQ test score should stay about the same throughout your life.

Addendum: I'm pushing 140+ as an IQ and I'm a 13 year old male. If you got the results from an online test they are likely inaccurate. You can take IQ tests at city halls and such.