Baby Shower Gift

I been trying to find on the internet a baby gift. Well, I remember my sister getting this gift for her wedding that was a letter and in the letter was blank with numbers on it which when she got to that number she had to open the gift with began into a story. I know this is a little brief. I was told they had one life that for a baby shower and I would greatly appreciate it if someone knew where to find this letter.
Thank You