Urgent help regarding Appointment for H4 visa stamp(for spouse )before marriage

[dahbal]

Hi Everybody,

As I you know US Embassy appointment waiting time for visa is increasing too fast.I am going India for marriage in first week of July. Can I take appointment for H4 visa stamp for my spouse now before marriage?
My spouse has written only first name in passport.Can I add my surname in her surname? Can she submit visa fee in HDFC bank with name after marriage i.e. her first name and my surname?

Please reply me back if anybody have any idea because I don't wanna add FNU before her name in visa stamp due to single name in passport.

Thanks in advance.

Regards,
Raj