The problem lies within the generalizations presented by the words “healthier” and “burdens”.

Many families with Downs children describe how much joy and love their Downs children bring to the family, how the family members learned to cherish what’s important in life, etc.

These families compared to many families with non-Downs children are quite healthy and arguably not burdened though they experience different challenges than other families.

EDIT: fix quote; change last preposition in second sentence.