Have you tried pushing her bedtime a little - ie keeping her awake an extra 10 mins on an evening (and seeing when she wakes up). So over a week or 2 her bedtime might become 7.30 = 5.15
Then in a month time it wont feel too bad (as the clocks go forward and you are starting the day at 6.15am)!!

Has it always been like this or just recently. Amy was always a good sleeper (waking once in the night but going back to sleep afterwards). However at christmas she was ill for the best part of a month with one thing and another, plus 2 teeth came in and she is unsettled. Every so often she wakes early and wont go back to sleep. What I do is lie on my side (almost in the recovery position) because you wont roll over (altho I havent even fell asleep because I worry about it) - and give her a cuddle so she is against my chest. I can hear her calm down and her breathing return to normal (as this is normally after tears and refusal to sleep in the cot). Then once she has calmed down i gently move away from her so she is flat on her back (and move my arm away). Then i give it 5 or so mins so she is properly asleep and transfer her to the cot. I know this sounds like she needs to be cuddled to sleep but
I dont need to do this every night, she settles ok at bedtime and sleeps well but when she wakes up in pain i think it helps.