You can control a Sky box via RS232 (directly via 9pin D or via an interface connecting to the RF2 socket) or some later boxes can be controlled by IP.
For control by RS232 you'll have to have some device sitting in the house that you can talk to via an internet connection, then ensure that it is on and booted, before you work out a way to actually talk to it to then control the Sky box. Even after you have accomplished all this you'll still have to learn how to write the RS232 command sequences. Here's a
link to the protocol ........ To me that seems like an awful lot of ducks to get in to a row. IP control works if you have a smartphone on the same network as the Sky box. Quite how you get that achieved though when the smartphone is in a different house on the other side of the village isn't something I know. Maybe tunnelling VPN? But again it seems like a lot of work.
The problem with both above is that neither address how to control the TV as well, and in both instances you'll still have to have the Sky and TV remotes out, so you haven't removed the cause of the problem in the first place which is the wrong buttons being pressed on those two remotes! You'll be fixing the symptoms and not the cause.
If I were you I would look at the simple promotes posted by footprints. Alternatively (
and this is something I have suggested to you on at least two other occasions) have a look at a
Pronto SBC RU890 (UK/European version of TS-1000). With it you can get rid of both troublesome remotes and program the Pronto with big and easy to read icons and a much simpler control layout.
One screen for Power ON that switches on the TV and the Sky box. It then jumps automatically to the next screen which is Ch up and Ch down and volume. On the same screen is a button to switch the system off, which then automatically jumps to the Power ON page once the sequence is complete. The touch screens are illuminated. The remotes take standard AA or work off a rechargeable docking stand. They're cheap too in the used market. This just seems like a perfect fit for your aged mother.