Tabby wrote:

If she can get any signal at all on a set top aerial, you'll likely
find a good loft aerial & amplifier is sufficient.

I agree, fwiw. A good "digital aerial" (as the bloke who sold me mine,
a few weeks ago, described it) costs £30; plus you need a few meters of
good cable: definitely worth a go at DIY, in the loft, if she's getting
a signal off the set-top at the moment.

John