I'd say don't make any sudden changes! That's where it all went wrong for us in moving from 2 naps to 1. She's very young for just one nap and its highly likely if you jump to one nap she will get OT very quickly and it's a lot of hard work to get back from that (check out the
2-1 thread on the naps board to see just how sticky it can get!).
Try limiting her AM nap first (e.g. to an hour or 45 mins) in the hope that she will go down for her PM nap better.
If that doesn't work then you could shift her morning nap closer to midday (don't move it more than 15 mins every 3-4 days) and let her have a catnap in the afternoon if she will take it, or a very early bedtime if she won't (5:30pm wasn't unusual in this house during the transition).
There's a thread on one of the FAQ boards about
10-11 month old sleep gone wonky that's got more detailed stuff on this.
Bottom line is - don't rush it! Hold on to 2 naps as long as you can
