FJ unless they are red, and inflamed i'd be hesitant to give antihistamines. They are an excellent medication when required, but not something i'd just give unless it was needed.

She does have a lot of spots. Poor little thing. I use stingoes, or stopitch, calamine is great too. Have you looked into a natural insect repellant that she can safely wear every day?

Does anyone else have bites? Could it possibly be something in her bed if she's the only one with them?