I used to do a lot of German cooking.
Hot German Potato salad is really popular in my family. Much preferred over American mustard or mayo style potato salad.
My GM used to make plain boiled potatos. Use waxy style potatoes. Cut in half if really large. Place in a pot and boil with skins on till tender. Drain and put back in the pot to dry off. Cool a little bit and remove the skins. Add salt, pepper, and melted butter if you like. (This is not a favorite of mine, just too plain for me) Occasionally she'd smash them up a litte to make putting a gravy over easier for the diner.
Potatoe cakes are very good.
My kids like the pan fried potatos cooked in oil with onions are nice and probably familiar to her. Look on Food.com and there are several references. I always start them with already cooked potatos that I've baked in the oven or microwave and then peel, slice and pan fry.