Gosh, I wish I could give you a straight answer Hun
It is unfortunate that moving to a bed has coincided with the 1-0, it is a tricky situation for sure. There are 3 approaches that I know of.
Return her to bed silently every time she gets out. I have tried this, and I tell you with no hesitation it is hard, and IMHO not the best way to go if you can avoid it. Firstly, it means she is getting attention, so it can quickly become 'a game' in her eyes. Secondly she may just find it upsetting and get cry a lot. Thirdly it is a battle of wills, and can take a long time.
The other way isn't easy either, sorry, but I think it is better. Just let her walk around the room and do her thing. Use your sleepy phrase, plus ask her to get back into bed in as few words as possible. Don't enter into any play or extra activities with her, just sit. Eventually most LO's will lie themselves down when tired enough. This may not even be in the bed, it may be beside you on the floor or wherever. But, the next night she will know what is going to happen if she gets out of bed and that it is not interesting or fun, and the hope is she won't bother in the end.
Thirdly, you could take her mattress out of the cot if you have room and let her sleep on it on the floor for a while. For whatever reason, it helps with some LO's, it's like flopping down on a mattress on the floor is less like getting back in, strange but true.
I'd try the earlier nap tomorrow and if it doesn't help I'd seriously think of alternating no nap days with EBT and an early nap day with later BT.
x.