C.F.
It's not only normal when they're teething but when they are sick as well. My son does this. All the kids in the daycare I work in lose their appetites sometimes several days before showing outward symptoms of a cold. But if this has been happening for 2 weeks, I would take her to the doctor. Sometimes babies have infections (such as an ear infection) and show none of the usual signs of it, such as the ear tugging or constant crying. The doctor can look into teething and infection to rule one or the other out.