Are you positive? The tank is cycled and I'd be doing 25% water changes every few days plus there's quite a few hiding place and I'd be buying a few more silk plants to add even more. Plus while the tank is only a 5g the girls are quite small even though they're full grown so they have plenty of swimming space. I wouldn't even be considering adding two more girls if I didn't think they would be able to live happy, healthy lives.
I'd love to upgrade to a 10g but in addition to not having the funds I'd need to convince my mom. But that would be amazing to have a 10g with a few more girls plus a snail. For now it'll have to wait.
This is the tank and you can see the two girls.