Can you go for a big walk or spend some time dancing around the lounge before you want her to nap - if she's not actually physically tired (no matter how worn out and ratty she may be mentally) then sleep will be a battle.

We also do books-on-the-mattress, with me reading a couple and then leaving DS with a large pile of them. It is much less painful than most other methods. And we call it "rest" as in "you don't have to go to sleep, just go upstairs and have a rest". Usually he falls asleep, but if not he's at least had a bit of a break.