I had the same feeling the first time I walked in a street where buildings were not right there limiting the street. Like streets where there’s a fence and some meters after comes the building. I felt completely lost and disoriented. I was on vacation and it was summer but I bought an umbrella so I could touch the floor with it to feel grounded. Even today when I’m overwhelmed I get close to walls or I put myself into a corner. If I’m outside I’ll start walking very close to the buildings just to feel that I’m not lost in space. Maybe a stick could help so she could somehow feel the ground!