In between all the sleeping, how does she behave? Is she hitting all her milestones? Walking, starting to talk? Makes good eye contact, etc? What does the pediatrician say about all the naps, etc?
My niece is seventeen months and she gets up around seven, then naps between ten and eleven, then again around two until four or five, and then is in bed by seven. So your daughter sounds normal. I know my daughter at that age slept like a log, twelve hours straight at night and took one 3-4 hour nap every afternoon. My friends with babies hated me because she slept so well!!
I was thinking, if you're nervous about something, maybe try a neurologist? Maybe her ears are very sensitive to sound or something; like too much stimulation is upsetting to her.
Good luck!