Question about rush & question about sorority at Ole

Hi. Honest answers please.I have a niece who will a freshman at Ole Miss this fall. She has an excellent GPA, excellent reputation,and involved in many activities at her high school. Do most girls going through rush that have great GPA, great reputations, and are involved in many different activities receive a bid to join one of the sororities at the end of recruitment? I hope my niece will be invited to join one of the sororities at the end of rush week this August. She is not a legacy of any sorority. I went to another university and was not part of Greek life so no idea if at the end some of the girls are not invited to join any of the sororities. Also is there a tier. I keep seeing top, mid, and low tier. Is this true. Is it ok to join a low tier if that is one’s only option? Or would it be better to be non Greek and not join a low tier if that is one’s only option? So will most girls receive an invitation to join a sorority at end of rush or are there many girls that are left with no invitation? And if low tier is a thing - is it better to be non Greek if a low tier is only choice? I want Greek so all of this I wonder for my niece. Thank you so much!\n\n\n\n\n