One of my favorite resources for when Mommy is busy, and a child needs to have something to do while they wait, is the "Draw, Write, Now" series. There are eight books in this series covering animals from all of the different regions on earth, many historical events and people, storybook characters, and many, many more things to draw.
Each drawing assignment is set up in a 2 page spread, with a step-by-step "how to" draw the figure. There is always a completed drawing for them to look at as well, for ideas, and to visualize "where they are going" in their work. Beneath the completed drawing there are 4 sentences that give information about the picture they are drawing. You can then have them copy those sentences, or maybe just one of choice, or maybe just do the drawing...it completely depends on you, the parent, and the interest/ability level of the child.
WOW, art practice, handwriting practice, history and/or science information to boot. You can't get much better than this to keep someone occupied; but, still in the mode of school, while they are waiting for Mommy to get to them. I also let them use these books as a fun activity if they are finished with their work early; but, it isn't free time yet.
We've also used a similar step-by-step approach to drawing from Usborne. Any of these are great options for you to have on hand. They are completely non-consumable, you just need some paper and colored pencils or crayons.
A look inside a few of the books. You can get them individually, or buy the boxed set, from Amazon.