I had to start capping lily's nap to 1hr at that age on order to preserve nights. She was doing about 11hrs at night I think, maybe 11 and a half hours. She is slightly low sleep needs.
Jack is definitely low sleep needs and doesn't nap 2 days a week at nursery, and then naps 45 minutes - 1hr 20 on the other days (more on the days after not napping and reducing nap length as the week goes on). Over Christmas he wasn't at nursery and napped every day, but only 35 - 50 minutes. He averages 11 hrs at night.