Make a holiday themed meal. You can make your kid's favorite or go with heart shaped food, which is always fun.
Enjoy a family movie night. Snuggle up with some popcorn and treats.
Read Valentine's Day-themed books. At bedtime or whenever.
Decorate! Let the kids choose the decorations and where they go. (Even if that kid is away at college)
Make a 'fancy' Valentine's Day dessert together!
There are more ideas for you HERE!