your female is just small, probably just young, my adult females are about and inch and half long from end of tail fin to mouth. size does sometimes vary thogh. good luck with her, female bettas have the best personalitys i think
Well, I have a female and I swear she's a male in disguise. Mind you she's the ugliest beast (er... fish) I have ever seen
My other female is tiny. Like guppydude said, she is probably young.
And a bit of advice, if you are getting into breeding, I wouldnt breed a HUGE femal with a tiny male. That's where some ass kicking will come in curtesy of the female!!
I've never heard of Bettas growing up to 4" but maybe they do.
My friend used my now deceased crowntail female betta to his male double tail. Mind you, we had some pretty awesome fry. I wanted to post pictures as they grew up... but yeah, apparently the neg's didnt turn out.