J.P.
When I worked at New Horizon, the kids wanted to continue their naps as long as they could. They stayed in the infant room until 16 months, and until then would nap when they wanted (usually twice a day). At 16 months they came into my room, and had to nap on the toddler schedule, which meant going to sleep between 11:30 and 12 (after lunch), and sleeping anywhere until 3 pm. Some woke up at 1... some had to be woken up at 3. They were all different (probably depended on how long they slept at night, and how early they got up in the morning). I would say around that age, if you would like to wean her (and open up your day more!), just start keeping her up longer, and she will adjust. She will want to sleep when she is used to sleeping, and an average toddler seems to take a 2 to 2 1/2 hr nap. (from what I have seen). After a year old, I think going down to 1 nap is fine, but not needed. It is more important that she gets enough sleep than when she gets it, and as long as she sleeps well at night, let her nap as long as she wants. Good luck!
J.