Your mom gripping the passenger door handle during driving lessons was fear and faith in the same white knuckles.

Two things were happening in that car at once. She was frightened, visibly, and she was also sitting in the passenger seat letting you drive, which is what trust looks like when it costs somebody something. People often read the fear as a lack of confidence in them. Usually it is the opposite, and the fear is the price of handing over the wheel.

When somebody is anxious about something you are doing, try separating the worry from the permission. They are letting you. Saying that you noticed what it cost them is easy to say and hard to forget.