A.J.
My son sounds identical to your daughter. Didn't sleep at all as an infant. Turned a yr old and has slept like a baby since.
At 19 months old he still sleeps roughly 8-8 and has a 3 hr sometimes 3.5 hr nap during the day. I too was worried if he was sleeping too much. Especially these past few weeks where he was sleepin' in until 9-10am and still going down for his 3 hr afternoon nap. But he snapped out of it & is back to normal. So don't worry about it too much. She just might need the zzzz's.
BTW right about 16/17 mths my son went through a month where he refused to take a nap & was up at 6:30am. I was so scared it was all over so like all the other moms said enjoy it while you can...Lucky for me I'm still enjoying it, guess it was just a phase:)