Completely understand, livebearers churn out a lot of fry!
I started with guppies, knowing full well what they're like, but I only wanted a little community tank, thinking most of the young would get eaten, and when a good amount survived and grew up, I'd take them to the LFS (I checked he'd be happy to take youngsters before I bought a single guppy!). But my adults didn't seem to eat babies, and I have a lot of live plants in my tanks (see profile pic!) so I ended up with way more fry surviving than I imagined. So I got another tank so I could sort into male and female. Then a third tank to grow out batches of fry before sorting into male and female, since 30-40 fry were surviving from each batch. But of course, the females can have fry every month, but it takes 2-3 months to raise each batch... it gets out of control quickly! Fun for a while, and educational for kids, but it gets wearing after a while...
Depending how attached you/kids are to particular fish, you can rehome/send the females to the store, and keep a male only tank. As long as there are plenty of hiding spaces and decent plant cover, males can happily live in a tank without females. The females can store sperm and continue churning out fry for up to - perhaps even beyond - a year, without seeing a male. And as you might have experienced, they can get knocked up at a pretty young age, so with six females, presuming you didn't separate the sexes quite quickly enough this time and they're all storing sperm... that's a lot of fry you'll be dealing with for a long time!
