K.M.
You don't catch a cold sore from a kiss on the cheek, even if the person had a cold sore. If you do come in contact with someone who has an outbreak and you contract the virus, they tend to show up fast. I don't know what your child has, may be nothing, but it wasn't something she caught from a kiss on the cheek.
Just for future reference a cold sore left untreated gets really bad, really fast. If she had a dot in the morning, if nothing was done, by the time the afternoon hit she would have a large, painful, sore. She would complain. They don't stay little for long.