I drove that path, and it takes for-ever (that was my only complaint).

I can relate to the motion sickness at too many extremely curvy roads, but far more noteworthy/amusing/critical about the area of which you speak was the part where I drove around a bend, and saw a sign that said there was a ferry ahead, and that it left only once an hour, ON the hour. It was 5 minute to the hour, and I hit the gas... and made it easily.

It would have been a sad hour had I just missed the tiny ferry that carts you about the distance one can hit a golf ball. ("Isaacs Harbour, NS" )

If wanting to go to Canso, from/to Halifax, y'miiiiiiiiight consider taking the main freeway, and then highway #16.

My path to Halifax along highway #7 late one night, just seemed to never end...

The skies were overcast, and perhaps my memory of the path would be more exciting had I driven in bright sunshine.

Again, and more directly in response to your question, I am somebody who would have been somewhat sensitive to the curvy roads your mother fears, and despite my impatience while on that road, I did not react significantly to any curves there.

Never been on that road, but my wife is highly prone to motion sickness due to inner ear damage sustained in an accident.

It makes a huge difference if:

a) she is driving (never gets sick)
b) sitting in the passenger seat (sometimes gets sick, depends on the driver)
c) sitting in the rear seat (always gets sick).

Good luck!