A.D.
I think anything you could do or send to let the family know you love them and that you're thinking of them would be well received...
anything from a journal for a mom to pour her heart out in... to a favorite photo.... snacks... book of prayers.... stuffed animal that has a bandage wrapped around it's head too (like she'll have afterwards)... sounds kinda corny but my friend's little one had leukemia and had to have a shunt put in her chest for the chemo treatments... and she got a stuffed animal with a shunt in it too so that she had a chemo buddy... making her the treatments even just a little less unbearable was something heartfelt and that showed she cared....
seriously, though, anything you can think of that will help the family... I'm sure it'd be well received.