Sleepy Baby

At the moment I am the only one awake in my house. The Husband has been asleep on the sofa for a couple of hours now and I really don't think Baby of Dreams is feeling all that well. She went to bed at 9:30pm last night, which is about normal for her. I had a meeting at 9:00am this morning so I left around 8:30am. Baby of Dreams had woken up a few times, but gotten herself back to sleep. When I got home I was expecting The Husband to have fed Baby of Dreams, who would have gotten up at 9 or 9:30am. I got home at 11:00am and she was still not up. I was in the middle of a phone conversation which wrapped up at 11:30 and Baby of Dreams was still not awake. I went upstairs to check on her, she never sleeps that long, and she imediately stood up looking like I woke her way too early. I changed her diaper fed her some breakfast and the Huband and I started putting together lunch. Baby of Dreams ran around being altogether too cranky for having slept so long. I ended up putting her back down for another nap at around 1:15pm. She didn't complain at all. It is now 3:35pm and she is still asleep. Is she sick? Is she going through a growth spurt? Is she sick and going through a growth spurt? She has never slept this much in one day. Is this normal every once in a while? She has no other symptoms of being sick. It has been, for the most part a very quite day.