NICU moms: How would you feel if you received an anonymous Mother's Day card?

Last year I made and gave a card to every mom in the NICU in the hospital I live near. I was going to do the same this year but I want to be sure that it's something that they will appreciate and not feel creeped out by. My sister has had 2 of her 3 children in the NICU and I just feel for the moms that have babies in there. I wrote a poem that is included on the card as well as a short description on the back that reads "This card was specially made for the mothers of Bronson Hospital's NICU Babies 2011 by Jessica H. who also wrote the poem "NICU Mothers" in recognition of their journeys with their children through the Neonatal Intensive Care Unit." Last year I did not include my address but this year I was thinking about adding it under my name on the back of the card in case someone would like to send a thank you note (my sister said she had another mom last year mention the card and said she'd like to send one but didn't know how to contact me) but I don't know if that would be appropriate or not. I don't want anyone to feel pressured to contact me or anything but I would like for it to be available in case they want to. Ideas? Opinions?