Lady Audrey is insane!

[Hexerin]

There's way too many adds for a single-player boss.

[Michel Baie]

Lady Audrey is more about mana management than the other bosses, since it's the only encounter where you have to slay her minions too.
Keep your best weapon for her, and the second best for the spawns. Pay attention to her, to shoot her the earliest possible - you don't have to kill all the minions for the heart to be vulnerable.
The less cycling between vunerable/invulnerable state there will be, the better.

And of course, don't be a sitting duck and dodge as most as you can. Even when shooting the heart.

Still, yes, it's easier said than done and she may be a bit tough for a level 2 boss.
I wouldn't nerf her, but I'd make her spawn at level 3...

[Ǵ̶͓̂͑lí̴̤̀̄́tcĥ̸]

Is this the giant version of the plant spores? I just got this game last week and I beat this boss on my first try yesterday (having already fought through many of the other bosses in prior runs) and yeah she is noticeably much more difficult than the others of her floor. It was very close.

The only minions you have to shoot for her to reveal herself are the regular tentacles, not the shooting ones she spawns halfway through the fight. I basically just ignored those and ran straight at the first tentacles and would just look at her real fast everytime I killed one, because as the above said you don't need to kill all of them for her to be vulnerable. As soon as she appeared I ignored all adds and ran straight at her with my most damaging weapon, then simply rinse and repeat.

The best way to avoid shots that track your trajectory (i.e. they lead you on) is to strafe while walking forward in a very sporatic zig zag. They shoot whatever direction you are moving at that exact moment, so if you wildy tap both directions to the point where you are practically running straight while jittering, so to speak (so hold W to move forward obviously, but tap A and D rapidly while doing it), they will never be able to track you correctly. Their shots will always veer wide, with the occasional one that might slip at you but would be easy to dodge.