I am currently on H1B. My wife, who is also currently on H1B (from different employer, she came here in the US on H1B as well) would like to switch to H4. She has been on a temporary leave without pay since last month so her latest paystub is a month ago. My questions are:

1) What is the process of switching from H1B to H4?
2) Who should file for the change of status to H4? Employer or myself?
3) What are the required documents?
4) What is the processing time?
5) Will there be any risks if she continues to be on a temporary leave without pay for another month or so before applying for a change of status to H4?
6) Do you have other recommendations so my wife can stay here on a legal status?