I get selected in Phd course. My area of interest is cloud security. There are two lectures whose area of interest is cloud security. I requested one of the supervisor, who has good record and has good publications, to take me as her phd student. She said that she doesn't have the vacant seat now but after 6 month she can have 1 vacant seat. She talked with another lecturer to be my supervisor and said that in these, 6 month, she will evaluate my performance and based on that she will make decisions. So, after 6 months, if she likes my performance, I can have two supervisor in which one is my original supervisor (which is mam to whom I requested) and another mam is my co-supervisor. If she doesn't like my performance, I can have only another lecturer as my supervisor.
The problem is that she is not 100% percent sure and she will evaluate me during this 6 months. I want that mam (to whom I requested) to be my supervisor as she has good knowledge and publications in good journals. Should I continue with this phd or quit? Any guidance will surely help.