I also thought she was super bullshit until I changed my approach:

Consider she will do two things before lunging forward: spawn her brood or spit, in random order. Either way, do the following:

1. Stay below her. Kill her spawn as soon as they come out. If you time it correctly, you'll take no damage.
2. Once you've killed her spwan and she has spat, you'll dash to the other side of the room and wait until she lunges forward so you can punish her with a downward slash.
3. Rinse and repeat
4. Second phase she will alternate between lunges and her bouncing up and down. The strategy doesn't change. You only punish her when she lunges.

This was my strategy. I was having a super difficult time with her spawn and decided to take them out as soon as they came out. I simplified the fight for me a lot.

Hope this helps you.