Sick platy???

[fishewoes]

Any platy experts?
Around a month ago we got a male and female platy. Pets at home said this was fine, but it turned out the male was hassling the female. Female was fine, swimming, eating acting normal, but was being chased a lot.
We then got 2 more females a couple of weeks later to help reduce the pressure on original female fish.
For the first few days all was fine.
Now original female fish has been acting strange for around 2 weeks. She just sits hiding at the bottom, refusing to eat.
When she does occasionally come out of hiding she looks in good condition, swims for a minute or so, but still doesn't eat.
If I do a water change she perks up for 30 mins or so, but bar that she's hiding at the bottom.
I've seen her eat a mouthful maybe twice in the past 2 weeks.
All other 3 fish absolutely fine.
Any ideas?

I'm way too over invested in these fish!!!
But I just don't get what's wrong with her.
Google says water condition, but that's fine and all 3 others are fine.
She's not pregnant as far as I can tell.
It's a mystery.

Bumping for you. I clicked on this as I didn't know there was a fishnet board!

Do you think she's scared of the girl fish? Maybe she thinks they've gone for a bit when the water is changed. Is the tank big enough?

I've been reading about Platys just now and it does sound like it could be normal pregnancy behaviour. Google says it can take a couple of weeks for her to actually look pregnant.

You are going to have a LOT of fishes!

I don't know if she's scared of the girl fish. I don't think so.
If anything she head butts the male one if he comes near and ignores the females.
I'm just worried that 2 weeks of hiding is too long to be pregnant.
She almost looked very pregnant a couple of weeks ago, but she's back to her normal size now.