NB and PEI in a week?

In New Brunswick you have to get off of the main highways. St. Andrews, just 1/2 hour from the Calais ME/St. Stephen NB border, is nice and there is a campground right on the water where you can see the vast difference in low\high tides. Lots there - Kingsbrae Garden, Huntsman Marine Lab - one of my favourite places in NB. From Saint John/Fredericton/Sussex you can tour the Saint John River Valley. Get a map and travel the roadways alongside the watercourses for the Saint John and Kennebecasis Rivers. There is a system of cable ferries (free) that make changing sides back and forth very easy. Hopewell Rocks is a great tourist site but not for someone with mobility issues. There is a trolley you can take from the entrance to the Rocks but then you have to negotiate a long flight is stairs to reach the bay bottom. The Tidal Bore can be seen from downtown Moncton where there is a seating area. Find the times of the tides and get there early because theres not a lot of nearby parking.

Cross via the Confederation Bridge (an experience in itself) to PEI. Anywhere you stay you'll only be an hour or two from the main attractions. Charlottetown is a must. The most scenic drive (IMHO) is from Summerside to North Rustico along the coast. Cavendish is a popular tourist area (Anne of Green Gables) with lots of things for kids but nice for adults too. In Sept it will be less-busy but also a bit cooler. Lobster Supper @ Fisherman's Wharf in North Rustico is a must for us every time we visit. Haven't tried the one in New Glasgow (PEI not NS), but hear it's comparable. HTH