Do you use a grobag? I put my ds in a long sleeve vest in the appropriate tog grobag and if it gets really hot, I put him in a short sleeve vest. If she is just sleeping in the bodysuit, maybe look for some without feet?
Depends how hot a person she tends to be - my DS is always hot so he's just in a 0.5 tog at the moment with either thin PJs or just a vest. Or you could try a 1.0 tog if she's not quite such a heathouse!