Samir, You are Absolutely right. I called up the BCIS customer service and they explained to me correctly. Only thing is since we do not know how long they will allow her to be in US, I will take 4 months ticket so I presume they wulod issue 4 months visa. They said if they give her 2 months visa then I need to file I-539 (extn of stay) and as long as I aply and even if I do not get the approval,/denial she can still stay here legally without any problems. If its denied she should be prepared to leave immeidately. If its approved then we are safe.
Thanks ,