yes bring on the praise today, make a really big deal of her good nap, that's a good idea. And maybe even a little treat- a special milkshake or juice or something? Just so that you can remind her tomorrow of what she got today.
Could you leave her door ajar so you can peak to see if she's in bed or out? If you do do WI/WO you'll need to keep a firm sort of attitude so that it's in no way a reward for you to be back in the room. Just get her in bed again, tell her to stay in bed and leave I think.
Sorry, don't have much experience advice, just brainstorming what I'd do if I were in your shoes.
xx