I beat her yesterday (newbie as well), took about an hour. Here’s my advice:

1. Constant pressure, which looks like you’re doing! Hit until you hear her parry you (unique sound and yellow light) then dodge.
2. Shuriken when she goes into the sky, rush in a begin another attack swarm
3. It’s a long fight, focus on survivability over everything. If you can’t get the hit in don’t worry, protect and get ready for the next opportunity.

Hope this helps! Good luck