Name Change after marriage and getting ITIN

[gautam1]

Hi All,

I am on H1 and my wife is on H4 visa. Now she wants change her last name with my surname. My question is :

After getting her new passport, Her existing visa will be valid or not ?

When should she apply for ITIN ? I heared through some people that ITIN will require only at time of IT filing and will get ITIN that time only.

Any help will be appreciated.

Thanks