On instagram I follow a page called 52.lives (someone mentioned this charity in earlier threads which is how I came to find it).
They do something similar to R, in that they request donations for items for people in need. This paticular charity use amazon wish lists so people can buy the items direct off the list.
I have attached the grid set up pictures below- nice and transparent eh?!. It's clear what they are asking for and why and then a little follow up picture with a thank you and explaining where the donations were spent. It just goes to show it can easily be done.
I appreciate R helps thousands of people a day
so couldn't possibly do a write up post about every single one of them hence the setting up of the PayPal in the first place. However she could quite easily even just once a week/month do a little grid post along the lines of Thank you for your continued support and donations this week/month we have managed to provide XYZ to this many families and this for another family blah blah you get the jist. It would not be time consuming at all considering she should have these figures logged with her accountant for proof that the money is being spent this way. Slightly off the topic but if someone even asks me to grab them something up the shop for them I make sure I give them a receipt with their change as I don't want them to think I've short changed them.
I'd definately say R has time to do this going by th content on her insta daily. If you have time to film yourself putting stickers on boxes mate....