如果在美持 B1签证期间先转为学生F1签证，等排期适合再结婚递I-130是否可行？
-Yes, but she still needs to wait for at least 90 days (90-day Rule) and then, file the change of status. If she can get the F-1 visa to enter US, that will be ideal. Thus, she can get married after 90 days and wait for the priority date is to be current to file I-485 during her study as an F-1 stduent.
这样多重转身份是否会引起其他问题，
-It should not be a problem if she files the status change applicaiton after 90 days later after she enters US using B1 visa.
反而需要更长时间？
-It may take a longer time to get the F-1 application approved.
Normally, B1 status allows her to stay in US for 6 months, so if the priority date becomes current during this period of time, she is OK to file I-485. From recent few of years, F2A category 排期 is very short. Most of time, the applicant can file I-130 and I-485 concurrently.
