Source: Open Peeps, Hand-Drawn Illustration Library

Open Peeps is a CC0 licensed graphic library of people. CC0 is the equivalent of Public Domain, meaning you can do whatever you want with the graphics.

The site does require an email to download, but you could download the package for your students first. In the Flat Assets folder there are several ready made people in .png format. To create your own with the parts, you will need to use a .svg editor like Gravit, Boxy, or Inkscape.