The sleeping through the night isn't something that you have to worry about. Babies generally take three naps during the day as well. Two hours naps is a normal length. One morning, one afternoon, and an evening siesta that's most often a little shorter, is fairly common.
Some babies need less sleep than do others. At this age in general, babies need almost 15 hours of sleep! I know it seems like a lot compared to what we need doesn't it? If your baby is especially active when she is awake, or growing rapidly (which can sometimes last for a while, don't forget it takes a long time to cut teeth as well) she may need a little more. Your baby is almost textbook here looks like to me.
11 hours at night, plus 2 for the morning, plus 2 for the afternoon and 1 in the evening or so makes 15, so I think you are pretty much on track. Some babies are also well-tempermented, so you can be thankful you didn't get one like mine that likes to take about 11 hours a day and is fine with it.
Here's one of my most used links: it's my favorite chart to give to moms dealing with
sleep issues with their babies