I don’t see the problem.
I don’t either.
Considering the nature of the tour, I would imagine it’s pretty routine to let people see and feel what cotton bolls feel like.
I don’t either. My (white) children have picked cotton at a local historic site. They’ve also ground corn and fed chickens. It was part of survival for both white and black people in this part of the country.
It would be weird only if Mrs. Northam singled out black children from those of other races.