Thank you everyone.
I agree that easy easy easy is key. I HAVE been speaking to her about what she does. She says she splits the meals on wheels meal because they are too big. I don't believe her. They aren't big and I've been taking her out for dinner and she can eat more than I do. Three courses, every scrap, no struggling. Her children have said she's like this with them too. I think it's more to do with prepping food. She has said she hates cooking but I don't think it's just that.
For her doing any meal prep ... she has a serious balance issue. It has a specific medical name. Standing for a while and prepping food (not having anything to hold on to) scares her. She has had some very very VERY bad falls. I've watched her trying to make tea, and when she lets go of her walker she gets instantly wobbly. On one occasion I caught her just before she fell backwards while she was standing facing the kitchen counter. She doesn't have the strength to pull herself back towards the counter when she wobbles backwards.
She also has arthritis in her hands, so she fumbles with opening and closing things (for example, unwrapping sweets, or popping pills out their blister packs). I've bought her a pill organiser and will ask her to get her carer in the future to help her sort them weekly. Tomorrow I'll do it.
Hearing - fine with hearing aids, and not too bad without either. Sight - needs cataract surgery but can read WhatsApp messages on her phone and Facebook etc on her phone, so will be able to manage packaging.
The suggestion of getting the carer to prep her a sandwich and yoghurt is a good one. I will also suggest her carer helps with defrosting meals. If I by any chance meet the carer before I go I'll ask her myself.
She used to have Wiltshire meals delivered but stopped because they arrive frozen (and I've been freezing meals!!). She found having to defrost first then cook them a pain. I've suggested she takes something out the night before and it will be defrosted the next day, then all she needs to do is pop it in the oven. She said she hadn't thought of that (!!) and would try them again because she really liked them. But as I said above I will also suggest she gets her carer to help with the defrosting if necessary.
I've written up her a plan of everything in the freezer now, so she can cross off items one by one and know which items need to be eaten first because I've also put down the dates. I've suggested she keep that system going so she has variety and knows what she has all the time. She can do that sitting down.
When I say she is as sharp as a tack, she really really is. She is the person I've known my whole life, being let down by her body and health. So she finds asking for help or accepting help very difficult. I have to be sensitive to that and her feelings. She also says when she falls, her overriding feeling when she knows she's ok, is fury and frustration.I think I'd be bloody pissed off with my body too if it kept letting me down.
I'm feeling overwhelmed and so sad for her. Wish we didn't all live so far away from her.