Hey, Afa. You were so kind to write to me, so I thought I would read your thread. Wow. An IH separation must be so hard. I remember when my H said he was moving out and it took him 2 months to do so. Those were the worst 2 months of my life. I was being super nice and loving, and nothing worked to change his mind.
Your upcoming bday (happy birthday) and the anniversary must be affecting her; maybe making her feel angry/guilty.
It's a tough sitch. I would try to avoid her moving out bc once she's out, things will get worse, but at the same time, take care of yourself and practice the LRT. That's my 2 cents. Good luck.