Yes I'd try a bit later, just see what happens... I tended to find that nights got shorter towards transitions, however each of mine seemed to have a different limit as to how short their night could get before needing to cap naps. You may well be at that nap capping stage already, but since she's doing lovely naps, I reckon you might be able to stretch that last A a bit, in the hope that you move the A she has at 5:30am to the evening
You could try BT at 7:30pm to start, and move later in 15min increments until you either see clear signs of OT (in which case we rethink and start capping one of the naps) or she starts waking later in the morning. The hope would be to both lengthen her night and shift it later, by getting her a little more tired before BT, if that makes sense.