bodenbetty do you think your dd might have reflux? It can affect them even if they aren't bringing anything up - and it often is worse at night because of lying down, and it may take weeks or months before you notice it.
Feeding her in different positions might help, also keeping her upright for a while after feeding (not actively 'burping', just allowing the milk to go down) and raising the head of her bed by a phone directory or something similar under the feet or under the mattress. Massage might be good but perhaps keep her head raised while you are doing it. Some people have good results from seeing cranial osteopaths but it didn't help my little one.
(My ds2 only showed any real signs of reflux when he was about 2 months old, and he was a 'silent' refluxer, which meant he rarely threw up, but he was obviously in pain a lot of the time. Night-times were hell until we saw a paediatrician and he was put on the right medication.)
here's a basic page about reflux: from the PAGER website
and another useful site by a mum to several reflux babies
but if you think this might be it, then I have plenty more pages you could look at - or just hunt for 'reflux' in the mumsnet archives!
hope that helps, also it might not be reflux but it's worth considering