Dear Mrs. Cindy,
Congratulations on the birth of your first child on 01 May. I am sure that you and your husband must be very excited at the arrival of a beautiful baby boy. The other members of the staff are pretty excited too and from what I heard, they are planning to pay you a visit soon. So be prepared to receive a lot of congratulations and presents.
The head honcho himself asked me to convey his congratulations too.
Yours sincerely,