Need help on status, please!

[speednab]

Hi,
First of all, thanks for reading my post.
I am in the USA on H1B status for another 4 years. My visa is expired and not stamped. My fiance is planning to come here as Visitor (B2) and then get married. She may be able to change her status from B2 to H4.
1. In case she cannot and I already filed my application for CSQ, how can I add her legally to the process?
2. Is it fine with her visitor status?
3. What if she overstays waiting for the PR?

best wishes to all
Speednab

[speednab]

As most of the time, people pass by with no answer or comment!

Thanks though