Giving her choices in as many things as possible seems like a very good idea to me!
As for the stinging, could it be an idea to ask for a different long acting insulin? (It's only insulin glargine (Basaglar, Lantus, Toujeo) that has this nasty sting, and I absolutely hated it! (And I was 39, injecting a child with stuff that stings must be much worse.)
I'm on Tresiba now, absolutely no sting and a more stable action for me as well. I also use Levemir, no sting either, but that one tends to be taken in split doses, morning and night.