Alexander just thinking about your DD's meal on Friday - if one of my DD's friends was in a similar situation I'd be more than happy to offer help in the way of lifts etc, or if lifts aren't possible (I know you live quite a distance from school) possibly have your DD for a sleepover after?
I would genuinely want to help, so don't hesitate to put a plea out to your DD's friends' parents, I would hope DD's friends would ask.
Sost that sounds like the perfect treat for you DGD. I hope you're feeling positive about your treatment, I am in awe of you keeping it to yourself all this time, you're truly selfless- nearly time for you to be looked after a bit now 
(Glad pup is recovering too!)