i bet if your friends siblings would just do like you said, drop off some groceries, she'd feel so much better. Or invite her to dinner on a regular basis, one less meal she has to make for herself. Like I said, a little goes a long way.
You're so right, I think these practical actions of caring from her sibs would make her feel abit better. She has 4 sibs that live locally. The most caring one that she feels closest in spirit...is actually thousands of kms. away.