Hand foot and mouth

How long after known contact with another child did it take for your child to develop a fever. A few weeks we barely missed they incubation periods with our babysitters kids and were luckily enough to not get it but this week they came into contact with 2 kids on Wednesday and Thursday who then got their fevers on Saturday and have hfm now. It is running rampant in the neighboring villages school which happens to be the same village I take my kids to for their baby sitter 2 times a week. I have heard so many different incubation times and when kids are and are not contagious. I am debating on keeping them from school for a few days to be safe but am not sure. They are supposed to go back Tuesday which would be the 4th or 5th day since exposure. Depending on if you choose first day of exposure (Wednesday) or the last day of exposure (Thursday)

Any and all advice is welcome.