Dear Yangfan,
I have heard that you give birth to a girl.I'm writting to extend my greatest congratulations and wishes to you.I hope you could get recovery as soon as possible.
I am ready to give you a hand if you would like to take my aids.Besides,I am planning to see you this weekend;and if there is anything you need,just let me know.I can not help myself to see you and the baby.
You should take more attention to yourself.Please give my best regards to your family.
Sincerely yours,
（your name)