They don't normally tolerate earprotection very well but you can give it a go. Peltor do a coloured helping.
I very early on got the kids to wear the kiddo's version of the 13.4 just so that they can hear you which they may well find reassuring.
I very much doubt whether some exposure to the noise will make them deaf later in life, but that is a risk which I am happy to take for my own off-spring.
After all they need to have something to moan about later on!
FD