Hi Gnawbone,
Putting up with the rages can be really tough. I'm sorry it's been going on all weekend.
It is great to see that you have been reading up on the lessons. It is important to know, however, that once your gf is dysregulated, there will rarely (if ever) be anything that you can do to bring her back down. She will have to bring herself back down. I know, this can feel really frustrating.
While you don't have control over what your gf does, you can control what you do. Two things come to mind: not JADEing and boundaries.
If your gf misinterprets your reasons for doing something (e.g., telling her about your parents coming over), you can state what you really intended once if you feel the need. Then let it go. Don't continue to Justify, Argue, Defend, or Explain.
In your current situation, it sounds like a boundary may help you. The boundary can be something like "I will not be raged at". If she starts to rage, let her know that you can't handle it right now (or something of the sort) and need need to go in the other room / go for walk / go <somewhere>. Just be sure
not to assign blame to her in the moment. Tell her you love her and that you will be back in <pick your time frame>. Then be sure to come back when you said you would. If things are calmer, great. If she rages again, do the same and give it a bit more time.
When you start enforcing your own boundaries, be prepared for an extinction burst at first. She will probably escalate her antics in the hopes of getting you to react as you used to. If you stick with your newly enforced boundary, she will eventually get used to the new way.
Read up on boundaries and extinction bursts in the lessons. Boundaries have helped me and lots of other members here.
Keep us posted on how you're doing, and feel free to keep posting!
