Letters to my children

I just read an article about a photographer writing letters to her children. I am so inspired to do this!  My daughters may freak out if I post it online, but I definitely think this is a great idea.  Building up our children is essential to their self-esteem.  Im pretty strict so I know my kids think Im crazy and overbearing at times.  Have you heard of anything like this and would you be willing to do this for your children?