I'm going to be building up a sorority soon. Since I need more bettas to breed, I might as well throw them all in one tank so I can have more room for males. But I only have 2 females at the moment. They get along, but one is a lot smaller so I'm afraid to put them together. :/
They're very delicate, too, so you have to be careful. Half the time I catch them by hand rather than net, so I've grown pretty used to careful handling.
Also, I use ghost shrimp to keep my tanks algea free. Most bettas get along with them well in my experience, and since you don't give them much attention, you may not even notice if some go missing. xD
I can't put shrimp with one of my females unless she's in a community or sorority or she'll kill them, but the rest do fine.