Personally, I think "mummy instinct" is the best guide. If you think she may need a check over by a doctor, chances are she probably does (even if all it fixes is mummy's piece of mind, it's a trip worth taking!).

By taking her to the GP on this occasion, I don't think you're in danger of "running to the doctor for every little thing". You know your daughter, and you're the best person to know if she's just not herself.

Hope she feels better soon.