Other than things like a protein snack, black out curtains, white noise, etc. (making the room better for sleep), I would look into diapers that hold more. Maybe overnight diapers, or a size up. Maybe give her a sippy half full instead of completely full.
Another thing you can look into is gently interrupting her sleep/wake schedule. There is a term for this, but I can't remember what it is. Basically what you do is go in to her room about 30 minutes before she typically wakes up and gently nudge her until she moves a bit. Not enough to wake her up, but its enough to rouse her from REM sleep. This interrupts her sleep/wake routine and can help her sleep longer. From what I've read, it can work in as little as 3 days, or can take a week or so. So don't expect it to work the first time. And of course its tricky business, and it means you have to wake up at 5:30 to get up to do it, but it can have a big pay off in the end.
My youngest started waking up routinely at about 12:30 every night when she was about 14 months old. She wasn't hungry, she just woke up and wanted to be rocked back to sleep. So I went in for about 4 nights at 12:00 and nudged her a little, and then left the room. It worked for me! She stopped waking up out of habit/routine every night like that.
I don't know if it will work for you like it did for me, but its worth a try. Good luck!