IH, this reminds me so much of he behavior of my ex-GF. Initiating sexual discussions only to pull back and go dark on me for weeks at a time. I always chalked it up to her feeling down or crappy about herself, and proving to herself that she could still "have" me. Once she proved that to herself she'd disappear again.
I am not saying you are Plan B since this seems very early into all of this, but some of her behavior and words tend to lean that way.
I think your new plan is a good first step. But a straightforward discussion is still something I think you should consider at some point. I think if you do it the right way, stay aloof and detached throughout it, it could net you positive results. And then you will know for sure what she is going after.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018