I think it is totally normal for a provider to dislike, or not "click" with a child. Hey, they are just people, in smaller bodies! Some people are not all that likeable, and it often starts when they are kids.
Having said that, I think it's important to recognize that, and ensure that you are not treating the child any differently than the rest.
I care for the kids, but I actually try not to form a deep, loving bond. Eventually, that child will be leaving, whether it be a year from now, or 4 years.