I would really change day cares. That's way too much sickness . So constantly there would be someone sick at that centre then.. No good. Just move her
Ds was always getting head colds at one place as a baby.. Always! So I moved him and it improved so much. I think the centres hygiene has a lot to do with it as well as the kids. They should be making sure babies/toddlers hands are washed well before every meal. Toys clean etc..