How did today go? Did it continue?
Infants will have their off days, when everything goes a little wonky. If it continues, and it's completely not like her, then I would go through a bit of a checklist--
1. Illness-- ear infections, colds.. etc
2. Growth spurt
3. Dev. Milestone
4. Change in routine, home life, rituals.
When these days happen, give lots of TLC, and lots of support and comfort. If it continues on, then look at making some changes.