Weeeeellll, most bettas are naturally agressive, but most females aren't very agressive at all. Then again, when I got my female betta to put in my guppy tank a looooooong time ago, she would go out of her way to attack the guppies, so I had to put her in her own little two gallon, where she lives to this day. So, as you have discovered the hard way, some female bettas are more agressive than others, and I think that the best thing for you to do is to get her out of the tank she is in now and buy her a tank of her own. It should be at least two gallons. If you want, you can buy a second female betta and put her in the tank with the shrimp and possibly a new otto and see if she gets along with them, since some bettas are agressive, yet some aren't. A few things to look for when looking for a non-agressive female betta would be: no other bettas, especially males, near her that act agressive toward her(i.e. flaring, etc.), since she may pick up the habit and become agressive herself if she is around other aggressors, and not flaring at YOU when you get close to her. If there are no aggressive bettas around her and she isn't aggressive toward you, than she shouldn't be extremely aggressive toward your fish.
Good luck and I hope this helps!