What should I write on these wedding thank you cards??!

Heather • Wife💍, Mommy to: London 7/6/18🎀 Dakota, Due9/7💙

I got married two weeks ago. We had a small wedding only 20 guests and could not invite all our family and friends. Some people still sent us congrats cards with money.

I have blank thank you cards and not a clue what to write in them! Thanks for your generous gift? Is that enough? Ugh help