Maybe I missed this - since the Time-Traveller couldn't go home did the Doctor simply leave her in 1974?
There was no further reference to the fate of Hila Tacorian (the time-traveller) beyond the fact that she couldn't go home. The writer simply decided to leave it out, I suppose (much like the writer of "Cold War" never mentioned how the Doctor got to the South Pole
Which didn't make much sense to me, of course the Doctor could have taken her home. Now whether he chooses to do that, or leave her in whatever time period of her choosing is another thing, but there is no reason he couldn't have taken her home. We've seen him change history before.