Cut the white card stock to a 5" x 6.5" size. Later you will be folding it in half.
Cut out some hearts from the red construction paper. You will need 1 heart for each card you are making. Make the heart smaller than the card size when folded in half.
Squirt some shaving cream onto a tray and add a few squirts of red food coloring to it.
Have your child swirl the food coloring around into the shaving cream. Make sure they don't mix the red in entirely or the cards won't have the marbled effect.
Have your child press down the card stock onto the colored shaving cream and then carefully lift it up.
After lifting the shaving cream-covered card, place it on a paper towel and use the flat long end of a Popsicle stick to scrape the shaving cream from the card stock.
When the excess shaving cream has been removed, put the cards out on a table to dry.
While waiting for the cards to dry have your children decorate the construction paper hearts you cut out earlier. Brush some glue on the hearts and then sprinkle glitter on them.
When the hearts and card stock have dried, fold the card stock in half and glue the glitter heart to the center. Shake to remove any excess glitter.