Check out this website:
How Much Sleep Do Children Need?
Its good medical advice (but you could ask your own doctor the same thing).
Here is the catagory your daughter falls into:
4-12 Months Old: 14 - 15 hours per day
While up to 15 hours is ideal, most infants up to 11 months old get only about 12 hours sleep. Establishing healthy sleep habits is a primary goal during this period, as your baby is now much more social, and his sleep patterns are more adult-like.
Babies typically have three naps and drop to two at around 6 months old, at which time (or earlier) they are physically capable of sleeping through the night. Establishing regular naps generally happens at the latter part of this time frame, as his biological rhythms mature. The midmorning nap usually starts at 9 a.m. and lasts about an hour. The early afternoon nap starts from 12 to 2 p.m. and lasts an hour or two. And the late afternoon nap may start from 3 to 5 p.m. and is variable in duration.
___________________
Like IADad said, what matters is that she is getting the amount of sleep that she needs altogether, not so much when she's getting it. The article says 15hrs is ideal, but its not uncommon for a baby that age to only get about 12 hrs of sleep. My son was still getting like 2 or 3 naps at that age, but every child is different.
If she seems healthy, she should be fine. But if you think she's really really tired, then maybe keep trying to get her take that extra nap. Or see if she'll sleep longer for the first nap? A dark, noise-proof room to sleep in always helps with that.
My son did not sleep through the night at that age. I let him do it in his own time, and he went down to only waking twice a night at around 11 months old and around a year it was down to once. Shortly after that, he slept through the night. They are only babies for a short while, no need to rush things.
They know when they are ready to do what. I have heard that breastfeeding can sometimes contribute to waking at night more often, BUT my son was bottlefed, so its really hard to say in the end. Like I said, what it comes down to is that every kid is different.
