Presumably she has a phone, if something is not available then you could ring her and say is there anything else you'd like.
And for every single item it would be torture
Op Hi, this is your newly acquired drudge, delivery driver and home shopper. I'm sorry there's no Eccles cakes
Old Age Pisstaker Do they have any Swiss rolls?
Op They're with the cakes, I'll go and look. ... No Swiss rolls.
Pisstaker get me some Jaffa cakes then.
Op they're in the biscuit aisle. Hang on... Yes they have them.
Pisstaker How much?
Op £1:50.
Pisstaker I'm not paying that, it's scandalous, they're only £1.45 in Asda.
Op They've got own brand ones for £1:10.
Pisstaker I don't like them, the filling sticks to the roof of your mouth. Now you'll be coming past Asda on your way back here and while you're in Asda, can you pick up some Lemon Sherbets and some of their tinned pears?
Repeat ad infinitum.
The op would never leave a supermarket.