that sounds kind of normal. have you tried feeding her when she wakes up at the feed 2hrs later when you normally give her the dummy?

do you unwrap her/take the covers off when you feed her? obviously you don't want her to be cold, but a little cooler can help them to be a little more wakeful. do you do any nappy changes over night? a change before a feed could help her wake a little more....i couldn't do that one because DS was hysterical by the time we got to the feed, but often i would change him in the middle of a feed (between sides).

sorry, don't know if any of that helps! some of it may just be reassurance that mum is there & available!