I agree with Karen. It sounds like this is causing you stress but doesn't matter to her one way or the other - if it did, she would make more of an effort.
If she ever asks you, if you'd feel better about it, you can always order a resupply item -- or just say there's nothing you need and change the subject. But I don't think you should feel badly about not ordering from her. Taking your orders just sounds like an afterthought to her and at some point she probably won't mention it anymore.
She obviously isn't thinking of this as a business, just a casual thing between friends. So if I were you, I'd think of it the same way.
In the meantime, you'll find a demo who communicates, keeping you informed of specials and sales, etc., and you won't have to feel frustrated anymore.
Hope it works out well for you, Sue!