You know what's more useful than putting potato peelings into a blender?
Putting them into some soil. If you peel with a knife [because of being unable to use a peeler - arthritis, don't you know - even though speed peelers are far easier to wrangle than a spud and a kitchen knife], they're thick enough to grow and if they don't, they provide extra nutrition for the bag/box/tub of soil. Same way if the potatoes are green (which you shouldn't eat - actual, real toxins), sprouting or squishy, cut them into roast potato sized chunks and plant them. It won't be overnight, but you could get several FREE meals out of something she's suggesting you puree. 10 kcals now (and I'm being exceedingly generous with that estimate) with a significant amount chucked into the bin because it is genuinely inedible like most of her recipes or 2000 kcals in 70-120 days?
And if you want maximum nutrition/vitamin C but don't actually want to eat the skin of fresh/edible potatoes - run a sharp knife around the diameter and then boil/steam them in the skins - they slip off once cooked with zero wastage and, because the highest Vitamin C levels are directly under the skin, you ensure that anybody eating them gets the maximum benefit from the humble spud.
Gluten free, protein, carbohydrate, fibre, vitamin C, B6, potassium, magnesium, calcium - what's not to like about the things?