Hi J.!
God Bless your giving heart!! Well, being that I am and have been in extremely stressful times in my household. I thought it would be nice to hear from someone on the other side.
Well, Jan L. had it right, and the absolute "best" idea! Second being the meals, third would be help with baby gifts for the daughter expecting.
I think if you would ask them (which I had some wonderful friends "ask" at times "we want to help, this is what were thinking", "which would better serve you"?) My husband and I are givers and when we were on that side of the coin there were times I did that. Sometimes you could be really surprised as to what they would pick. However, there are people though, that would choose the lesser because they are really embarrassed to say. Even though your heart is to give more and you can afford it. But it can be awkward for the person receiving to admit what they could really use. A lot of that depends on how long you have known eachother and your friendship.
But if you really want to surprise them and not ask them directly. By far I would say to get them the weekend away. Those prices that Jan L. was mentioning were reasonable. Here's the prospective from one who is in it right now. They would love a night or weekend to have some R & R AWAY from their problems or stresses. How about this, or away from the people or things that cause stresses (even phone calls)! Sometimes getting away can be just the re-charge you need to be able to come back home and face it with a new prospective and or the strength and energy to face another week, month, or year!
Hope this helps hearing it from one who is in it and would love a weekend away! Your a wonderful friend and I am glad to say that my wonderful friends have and are doing some awesome "acts of mercy & love" on my family's behalf.
God Bless You and Your Efforts!
A.