Usually we don't cap naps when they go to one nap (not until much much later/older) and a 3hr nap is fine "by the book" but if it is causing problems longer term then perhaps it would need something changing a little. As it is so new I'd leave it long and see what happens.
Often set nap and BT works better once they are 1yo and on one nap so rather than working on A times move to a set nap time.
You can kind of guess when to put it, maybe 11.30, maybe 12?
Did she really need a CN that day? (day 4) I wonder if an earlier BT at 7pm might have been an option as she'd had a good 3hr nap.
It does take time to settle into one nap so I think go with the flow a little, maybe set nap time but don't change things up too much trying to "fix" the WU and BT if that makes sense.