My cousins are 7 and 9!
I got a 1/2 gallon dual tank with a separator for them, so they each get a 1/4 gallon twice the size of the prego jar xDD and they have pretty glass pebbles at the bottom! They seem to really like their new tank. Also my baby cousin (who is five) and lives with me has yielded his betta for me to take care of, Yoshi (the betta) has his own 1/2 gallon tank, the lucky fish xD.
I'll post pictures when I get home from work this evening! Also if I have time I'll go pick up some new food for the three of them.
Yay for frequent water changes haha