hi matthew,
what happens when she wakes between 5 adn 6:30 am? does she go back to sleep?
i'm not an expert on this, can only tell you what my experience has been. if ds was up vastly before the "agreed upon time" i'd try my darndest to get him to go back to sleep. if he didn't at least i'd try and get him to be in his bed, alone. then i'd have to adjust his day routine. if he slept well past his time i WOULD wake him up (my son that is). i always allowed a grace period of an extra 30 min and just assumed that he needed it for whatever reason. i wouldn't leave it too late, as in more than 30 min at this young age. once my kids hit about 9 or 10 months and were operating on less naps, or especially after switching from 3-2 or 2-1 nap and battling extra tiredness i let them sleep however long they wanted.
the overall goal is a 12 hour day and a 12 hour night. this istn' true for everyone, my kids currently sleep more than 12.
if i were you, i'd see if an extra 30 min or so in the AM affects her PMs, if not, you're golden, if yes, you can always start waking her up again.
HTH good luck