Yes
There is a handicap parking lot that is very near the boardwalk, so if you can park here, getting to the boardwalk is not a problem (the lot is to the left of the bathhouse building). The beach at this point is shallow, so your cousin could stay on the boardwalk yet be able to view people in the ocean and feel the breeze off the water. As Nectar says, the beach does not have mobimats in this area, so going onto the sand would be problematic. There are restrooms and Two Dudes (?) concession shack nearby.
You'd be fine for the boardwalk area. The water and sand would be the obstacles!
Thanks! Your answer is awaiting moderation.