Is it okay to consider "just watching" or "only part of it" as participation?

"Participation" doesn't refer only to doing the same thing the same way as everyone. Watching and learning, taking on just a part, joining for a short time, being involved in a different role—this partial participation is fine participation too. Start from a form the child can join without strain, and gradually widen it. The view of searching for "in what form can they participate?" rather than "can't do it means not participating" grows the child's experience and confidence.