What happened at first when I first started owning Bettas, I only had Tropica in a 5-gallon tank. My Mom and I decided to get two more female Bettas. We released Aqua first -- Tropica chased her around the tank for a little bit, and then they started fighting. I had to quickly release Aqua into the 2.5-gallon I actually had set up beside it (and I had been planning to use it -- however, my Mom was all like, "One tank; that's it," or whatever, so I gave it to her to put in the living room later). Aqua explored, and then, we saw Tropica going after Taffy (who we had released while Aqua and Trops were fighting). My little sister and I got her out of there quickly, but she flopped out of the net and landed on my knee, and fell into my bean bag chair!
We dived after her and absolutely *THREW* her into her little cup, and then we put her in my Mom's tank downstairs. Later, Aqua came in. They were the best of friends. <3
Now, after my disastrous sorority results (won't bother to explain, at least not right now), we put Queenie into the tank. Aqua flared at her every day randomly for quite a while -- it was quite funny, actually!
She would just randomly, and slowly, come up behind Queenie and *FLARE*. XD All three of them were the best of friends until Taffy died, recentlys.
Now, Aqua and Queenie still like each other a lot!
^^;
Even if things don't go right at the start, they *might* improve as time goes on!