Regarding sourcing the parts, there are online services available to order 3D-printed parts as you would a PCB. The *.stl files are available in the wiki. Though with how accessible 3D printers have become — the well-supported Ender 3 is available for under $100 at Micro Center — you may want to consider taking up printing as a family activity.
"Assembly Instructions - how to build a Blossom. In our experience, this takes about 2-3 hours for first-timers once you have all the parts cut and printed."
This is just my opinion but I feel it would be clearer if you wrote something like:
For a first-timer who can crochet or knit it might take:
1. 1-2 hours to cut the wooden parts
2. 1 hour to print the 3D parts
3. 2-3 hours to assemble the 'skeleton' of the robot
There is a guide available in the repo's wiki: https://github.com/hrc2/blossom-public/wiki
Our contributors' forks and extensions may also be useful:
https://github.com/interaction-lab/blossom-public
https://github.com/interaction-lab/BlossomNav
Regarding sourcing the parts, there are online services available to order 3D-printed parts as you would a PCB. The *.stl files are available in the wiki. Though with how accessible 3D printers have become — the well-supported Ender 3 is available for under $100 at Micro Center — you may want to consider taking up printing as a family activity.