mandatory addition of husband's (US citizen) surname

[ssanga]

My daughter has been living in USA since 2004, initially on F1 visa. now she is married to an american citizen for the last two years and has got green card. she is now employed in a university as associate researcher.
She wants to renew her passport and wants to retain her maiden name and does not want to add the surname of husband who is a US citizen.
Request you to please advise the procedure for the same.