You will need:
White Card Stock
Colored Construction Paper
You [and your preschooler] will do:
Have your preschooler cut out a rectangle out of card stock for the "My heart" part on the front of the card. Use the black marker to draw a large heart and a small heart on construction paper and have your preschooler cut them out and glue them together.
Cut a piece of card stock into a 5 x 8 inch piece and fold in in half, making the card. Have your preschooler do as much of the writing as they can.
For the pop up portion: Cut a 1 x 4 (ish) strip of white card stock and fold it into a rectangle. Glue the loose ends of the strip to the inside of the card. Phew, you follow? It's not as hard as it sounds:)
Below: My 7 year old daughter's version.
She did this all by herself, just from looking at the one above that my preschooler and I made.
I don't tell you this so that you can think she is awesome [but she is], but so that you can age gauge it:)