Your daughter is not blinking voluntarily and she will not be able to offer you any rationale. This may indeed be a tic - i.e., an involuntary muscle movement - and it may well be benign (most motor tics are). But it deserves evaluation, first by the pediatrician and then perhaps by a pediatric neurologist. While the eye blinking could be the beginning of what may develop into Tourette's Disorder, there is no reason to think so at this point.
My 6-year-old son has been blinking with both eyes simultaneously for about a week now, on and off. It does seem to be worse when he's watching television or outside with bright sunshine. At first, I attributed it to dry eyes and used eye drops on him to no avail.
I emailed his teacher and asked if he's doing it in kindergarten. He isn't. So, now I'm really confused and wondering if we should just ignore it or take him to an optometrist, his pediatrician, or someone else.
My son has also begun blinking excessively, and we have an appointment with the doctor - before I go in I would like to know what it is they will be looking for exactly and if there is anything I should be doing. Also what would make you think that it would be Tourettes - would it be a combination of other symptoms as well?