Gerbils are not nocturnal, unlike hamseters, which means they are awake during the day more.
We have two gerbils and 5yo DD loves to watch them. She isn't really able to handle them though - they can scratch or bite if scared, move very fast so esasy to escape from a child's hands and need holding reasonably gentle. Ours don't actually enjoy being handled. However 5yo DD des enjoy helping clear them out, putting in new things for them - they go through toilet roll inners daily! - and she also sorts their food and water out every other day.
You have to be very careful with what you buy to hosue a gerbil in. They will eat anything and everything. A plastic herbil style home is not suitable. You need a proper gerbilarium for them.
Gerbils are very easy pets to have on the whole. Very clean, they don't smell, they can be left for 2-3 days with no problems (just leave food and water), portable and easy for smeone to look after for you on longer holidays (can easily go a fortnight without being cleaned out for example) and they are fun to watch tunelling and playing with anything you put int he gerbilarium for them to play with.