Maybe one of the twins is sick?

In January we added another set of kitty sisters to our household, we call them the 'twins' because they are identical .
After much hissing, spitting and poofy tails they have settled in nicely with our other 2 sets of sisters. The pecking order is really quite funny to watch!
One of the twins, Bonnie, developed a watery eye on friday night. No mucus, just clear liquid. I woke up this morning to Bonnie sneezing in my face. She has eaten, drank and used the litterbox. She's not sneezing alot but gets off 3 or 4 good ones when she does. She was very active all day yesterday (normal) but seems content to lay on the chair blanket this morning (not normal). I just checked her nose is it's quite warm instead of usually being on the cool side.
Our 10 yr old girls and 7 yr old girls have never been sick.
We really need some suggestions and help here.
thanks so much
carole in atlanta