I have pregnant mollies but I don’t know how to tell when to put them by themselves.

[af2018]

I just finally rehomed the male today! I had him separate from my main tank with a couple females in a 10. One day I noticed a really tiny baby and one of the fat females was thin and wasn’t getting along with one of my still fatties. Just the one ever came I’m assuming they ate the rest but idk. I ended up getting myself down to 1 fish tank but in the process I played musical tanks basically until they all had to be housed together again temporarily. These females look very pregnant. Last time 1 had a baby aggression started in my tank. I do have small quarantine tanks I can switch them to but I really don’t know how to tell when they’re ready. Also some of these females I feel like have been pregnant for longer than 60 days but haven’t had babies yet. Are they even pregnant at all? The male was a strong swimmer he loved all my ladies and spent a lot of time with each. His attention span was the “ooh something shiny” type when he’d see another female.

 

[Andy Sager]

If they were with a male, the odds are they are pregnant ( or holding sperm.) The reason they probably aren't delivering any fry is because they don't feel secure in the tank to let them loose. I see a lot of nice decorations in your tank but nothing floating at the top that would be where the females would want to birth their fry. Get some frilly floating plants ( real or fake) and you should see a difference in delivery rates.
As for moving females, there is a lot of stress involved in moving pregnant fish so if you were going to move them, it should be earlier in the pregnancy rather than closer to birthing time. Best is not to move them but add a divider in their main tank with extra frilly plants or spawning mops so the females will give birth at a more " normal" timing.