I have two thoughts. 1) She may be going through a milestone development where usually kids sleep more (crawling, verbal development, etc) but she may be responding by fighting it. I agree with the others that teething could cause it. 2) If this goes on and her irritability continues, she may be struggling with yeast (can be caused by an antiobotic or vaccines) Generally, pediatricians disagree, but I proved it with labs and treatment with my kids. It totally affected their sleep.
Hope the motrin helps and it is just short term teething or development. Another thought, if you put her in a carrier against you and take a walk, will she sleep? Sometimes the imflamation from teething is better if she is upright and the comfort on you lulls her.
Good luck, J