my dd also dropped her day sleep at 27 months but would sleep in the pram. I also had ds at that stage so I would just take them for a walk every day at about 1pm and get dd to have a sleep. This worked a treat until she started not needing a nap at three (and now I hate it if she naps because she's up until 10pm).

What is the house like at 10pm? Lights and tv on? Maybe try keeping it dark and quiet for a week and see if you can break the habit of her waking up completely.

Good luck.