Women who have carried children tell me that every little pain in the feet and legs get multiplied the nearer you get to the birth.
She sounds pretty tame so you won't be stressing her just checking the foot every day. (I assume you are not tipping her up, that's always to be avoided in heavily pregnant ewes.)
So as long as the foot doesn't seem to be infected, the ewe can get to food and water (if not, put food and water near to her so she isn't reducing her intake), and she doesn't seem distressed, monitoring would sound like the best plan.
She may well be completely sound once she's lambed. If not, you can have a proper look once the lambs are born, licked and fed, and she has bonded with them.