>>> There is no such thing as a "digital aerial" even though many TV companies offered to fit one in their adverts or on the side of their vans
I agree that there's no such thing as a 'digital aerial' (and that many aerial fitters tried to con people into believing that there is).
However digital TV transmissions use different frequencies to the old analogue transmissions. Since the lengths of the elements of a TV aerial should be matched to the frequency range that the aerial is designed to receive, an aerial specifically designed to match the frequencies which are now in use is likely to work better than one which was designed for the frequency range used by analogue transmitters. (i.e. while it makes no difference at all, in terms of aerial design, as to whether the incoming signals are analogue or digital, the actual frequencies which those signals are using do need to be taken into account).
The vast majority of aerial cables terminating in living rooms of house are likely to still have a usable aerial at the other end of them, so it's likely that Smow will be able to make use of the cable she's found. However (since the aerial will be pointing to a different TV mast to the one which has previously provided a signal for it) she'll probably need to perform a full channel scan in order for it to 'lock onto' the signals.