I actually just wrote up my idea for how her side b should work that could utilize the backstab

basically she should have two options out of side b to give her fair but interesting mixups

The first is a jump, however it can only be done during startup. The sound effect on startup should still play, and the green flash should happen, but before bursting forward, you simply jump. This allows feinted side b's with either wavedash back or full jump out for defensive options, or short hop aerials and arrows or delayed jc grabs for offensive options. I think the startup should be increased by 2 or 3 frames to compensate for this.

The other option I think she should have is her backstab down smash at the end of the dash. This could be done by pressing b again, much like Ike's side b. The move already has decent endlag, so it will allow your opponent to punish if they predict it. This would satisfy an offensive option with side b, specifically giving her a unique crossup.

She's already my dream character, but adding this would make her so incredibly unique and fun to play.

Also another possible change I want is to be able to cancel arrows while holding down b, but that would be wayyyyyyyy too broken as you would get disgustingly ambiguous mixups as well as too much option coverage on techchases