I think friendships naturally ebb and flow too, so it doesn’t necessarily mean there’s a big problem if she needs a little more time for herself or whatever. I think you might be possibly panicking and looking for signs she’s backing away but the thing is even if she was backing away there’s not really anything you can do about it.

I do understand your fears btw and I’ve also got anxiety around some friendships, but sometimes we need to give space. She sounds super busy to me, I don’t work full time and know if I did I’d really need time to recharge. Maybe ease off a bit and keep in touch casually?