Should you be looking for a last minute valentine idea, how about bookmarks?
This project was simple, inexpensive, and we love the way they came out! O, age 6, was able to make bookmarks for his classmates completely independently. N, age 4, required a little help from an adult but not much. I did the prep work by cutting the paper paint color samples to the correct size and cutting all the lengths of ribbon the same size. The children did the rest of the work using a heart-shaped hole punch for each colored square and a regular circle hole punch for the ribbon at the top. On the back of the bookmarks O wrote the names of his classmates along with his own name. N just signed her own name, as all the bookmarks are essentially the same. Not differentiating the bookmarks to individual students will make it easier on her when it is time to give them.
What do your valentines look like this year?
*In the interest of full-disclosure, I have to say I originally saw this idea on Pinterest. However, I have been unable to reach the original blog post.