Oh...how old are the girls, and how long have they been in there?
Please don't take offense, I'm only mentioning this as a just in case measure. :) I don't want to seem like I'm overstepping my bounds and giving advice that may or may not be wanted. :)
You might get really lucky and just have laid back girls. Or something could change...and then they'll start going after each other and you can end up with a tragedy very, very quickly. :(
Your tank looks a little bare in the plant department (silk or live). Normally you want to have LOTS and LOTS of plants in a sorority, plants at all levels, enough so that it can be somewhat hard to see the fish. This is so that if someone is chasing someone else, they can get away or out of the line of sight of their attacker, and be "safe".
I know you mentioned that your son enjoys watching them a great deal, with lots of plants though, he'll still be able to see a few of them (probably not all), but he might also enjoy the challenge of finding them in their hideouts. :) So double benefit, he gets to have more fun with his fish, and the girls stay safe. :)
Your girls are cute though, and you've got a nice variety of colors. :) I love the bright blue one and the lighter bodied Cambodian. :)