name change in passport 4 days before visa interview

[saralapeach]

Hi :
My mom is scheduled for her visitors visa interview in the next 5 days.But since her name is spelled differently in the passport , we are planning for a name change in her passport.Now they say that if her name is changed in the passport ,then the passport number will get changed.
My question is
1) Since all her visa documents which we had sent her are referring to her old passport number.
Would it be a problem if she changes her name now ,that only 4 days are left for the interview and that too with the old docs still referring to her old passport number.
2) Will there be any problem if she submits the documents bearing her old passport number to the visa officers during her interview.
3)Does she have to take both the old passport and her new passport along with her to the interview?
4)Or should we change all the documents to refer to her new passport number and then submit those docs to the visa officers.
Please let me know if anybody has faced such an unique problem.Your replies would be very welcome .
Thanks.

[immihelp]

You said your mother's name in passport spelled differently. Differently compared to what?

Has she already received new passport?

If the name is same in all documents (even if spelled incorrectly), that is OK.