Hi there - sorry it looks like I abandoned you but I've just been a bit snowed under.
I would still keep the nap at 10.30am - perhaps with a flexibility of 15 mins either way if you feel more comfortable with that?
The days she woke later, 7am, and had a nap at 10.30 (but too short, maybe UT) could be indicating to her to wake up earlier which in effect means she increases her own A time to account for the 10.30 nap. Really if she is laying awake in her cot not calling for you and you were still sleeping then you wouldn't know how long her A time was because you wouldn't know she woke at 6am rather than 7am. In some ways it is helpful to know when she wakes but in other ways it is not so helpful, it can make parents worry about A times and OT etc.
If she needs a longer first A time then this is either going to come from her waking earlier or you moving the nap later - it isn't going to come from giving her an earlier nap.
Times, A times, nap times are not set in stone and although we often use them here to try to judge the best routine for LO it is important not to get too wrapped up in them. This for instance:
This morning's A time was 4 hours and I got a 1h20m nap.
Seems like a pretty good nap after 4hrs A time. I would have thought with say 4hrs 15 or 4hrs 30 she could well get a more restorative sleep of 1.5hr+ maybe a full 2hr nap. I would take from this that a slightly longer A time is not a huge worry.
Of course it was only one day though so we shouldn't put too much focus on one A time and one nap.
So the last 2 morning she woke at around 4, I ends up having to nurse her but she went back to sleep until later 7 am.
I probably would have used this later WU as an opportunity to move the nap later, but easy to say in hindsight and you might prefer her to be up at 6am rather than 7am? I don't know. 7am sounds better to me, but it could result in a later BT down the line.
Just as a rough guide, with a longer first A time, shorter second A time and shorter still last A time the result is later BT which also then allows for an 11hr night, it could look something like this:
WU 7
A approx 4hr 15 - 4hr 30
S 11.15/11.30 - 1.00 (or even 1.15 or 1.30 if a 2hr nap)
A 3hr 30
S 4.30 - 5
A 3hr
BT 8