Hello shitlords

I've been struggling with and combating oneitis for one of my 3 plates since I met her. I believe that I have been keeping it in check, though I haven't been able to eliminate it yet. She's been a sexually-active plate for about a month and a half. She knows we're not exclusive and I know she's recently been pursuing a girl on the side. My SMV is higher and she is aware of this.

Honeymoon phase was great. She was loving, caring and put in a lot of effort. I've noticed that her efforts to reach out seem to be dwindling - though in-person she's still loving and affectionate. I know she does tax-related work and her busy season will only get busier for the next month. And she's a single-mother (and I'm aware of TRP's general advice when it comes to SMs).

Yesterday, I texted her saying "Tonight."

She responds with "I can't, sorry."

I say "K" and leave it at that, and haven't reached out or heard from her.

She didn't offer up a reschedule, and I'm not sure if her vibe is busy (the rational me says this is unlikely) or less interested (the emotional me doesn't want to admit this). How soon should I soft Next? Any advice?

tl;dr Plate has been more distant recently, and I think I'm chasing her whereas she used to chase me. When should I move on?