I finally did weaving with my third grade kids. I went to a teacher workshop at the Mingei Museum and the facilitator gave us each a bag with the beginnings to do weaving project with a group of 24 students. There were 3 skeins of yarn and 24 cardboard looms.
I had a few looms of my own which finally made this do-able for a whole class. The first day, I had no adult helpers so we identified our third grade table experts who were able to assist students who needed help with the concept of weaving on a loom.
The next groups of students came a few days later. I reached out to classroom teachers and asked for extra volunteers.
It was great to have several adults each period making the process much easier and more enjoyable for everyone.