[cheekyangus]

Indoor aerials can be perfectly fine, but they vary depending on a number of factors. I've got one Freeview device connected to an indoor aerial that's 20+ years old. It's worked steady as a rock through all the changes since Freeview came to the area with switchover in 2011. It's almost always been on the windowsill. It gets a great signal from the local Relay transmitter.

If you don't have a spare indoor aerial of your own you can try out with her, see if you can borrow one from a friend/relative and see how well it works. It's worth a go before getting the roof aerial work done.

I have to say I've never had to manually adjust anything regards position. If it got moved it was due to housework, and it usually ended up right back where it was, same angle, etc.

I know this isn't the same for everyone, I'm not saying it is.

We do actually have 3 devices hooked up to a roof aerial, and they get a signal from the nearest Main transmitter, but we're the only ones with our aerial pointed that way around here, and that's thanks to an installer that was willing to try. We aren't actually in the likely coverage area. The indoor aerial would likely struggle receiving from the Main transmitter even if the hills weren't there I'd imagine.