Heya
I think your LO is ready for an A increase. Those short naps at this age, and after that length A time sound like UT, then after a few LO gets OT by BT.
It's great your LO sleeps independently at BT, it shows she is capable, a d once your EAsY A times are right she will probably drop off quicker.
Do you have NW? D you feed at night at all still?
I would try gradually increasing her A times closer to 3 hrs, do the first A and if you gets good nap then you an increase the next A. If not then keep the second A short and offer the CN if needed.
You want to aim for something like this
WU 6.30
Nap 9.15/9.30 for 1.5 hrs or so
Nap 1.45/2 for 1.5-2 hrs
BT 7-7.30
What do you think Hun?