The second boss to me was pretty easy IMO. I only died the first few times I tried it with different weapons, but if you have:
The stun gun + shot gun she is so easy to beat. To beat her easily you don't have to do a thing but stand where you start. Then have the stun gun in hand, as she charges you just stun her. Then switch to the shot gun at close range, and keep firing at her head, and she will run away to recharge. Reload the shotgun, swap back to the stun gun, reload it and wait for her again and repeat. I think I had to reload the shot gun 4-5 times to beat her. I took only minor damage each encounter when her typhoon partially goes off when you stun her.