This is a really dumb situation, and I have no idea what to do about this.
Myself and my jethani do not get along. (surprise). Over the past twenty years we have had a love/hate relationship, stay out of one another’s business and lives. My husband and his brother are on hello/shello terms.
Okay, the problem is this. My SIL has had a social media account (FB, Twitter, etc) for a few years now. A while ago, she made some changes to her account; ie her name. She changed it from the name she was using to another name. She also added a college to her profile (she has never attended this college, ever). People open their FB accounts under their real names, or use another name as they see fit.
The current name she is using on her accounts is the same name, the legal name as my daughter. The college listed on her profile is the same as my daughter’s.
My daughter is a college student. Her account is a bona fide account under her name with her educational institution listed. As you all know, many classes require you have a social media account as a way to stay in touch with instructors, advisers, peers and more.
When one searches for my daughter’s name, the name being used by my SIL also comes up. People are confused as to why my daughter has multiple accounts,and since my SIL comes up first in the search , people add her (my SIL) as a friend. 
We do live in the same city, though we are miles away. We have some overlapping social circles, some same friends etc. I myself do not maintain a social media page. My SIL is older, and has “friended” many of my daughters friends, who have added her. Once they realised that this person is not my daughter, they unfriend my SIL or keep her on, as people love to have friends.
My daughter is involved in community service etc,and other things, so is often contacted through social media. This happens usually someone does not know my daughter too well so they search for her on FB . She does not get the requests, interview notices etc as the messages go to my SIL account. We became aware of this a couple of months ago, when Person X met my daughter , was frosty towards her and said, “At least have the decency to respond, you came very highly recommended”.
My daughter was very confused and responded that she had not received anything.
Person X pulled up the sent messages and the person it was sent to, which turned out to be my SIL account. My daughter said, “That is not my account, it belongs to someone else.”
Person X, “Your name is so unique, there cannot be two of the same, and at the same school unless you have multiple accounts.”
Daughter, " No it’s someone else using the same name as mine."
Person X " Well I only know one other person with the same last name, and it is XYZ".
My daughter, " Yes, that is the person who has this made this account, and she is my Aunty."
Person X, " I know her very well, and that is not her real name, why does she have an account in YOUR name?"
My daughter ..No comment
(BTW, we have a veryyyyy unique name, so only a handful of people go by it).
The above scenario has happened a few times now, or someone will tell my daughter “I didn’t know you and your Aunty shared the same name”.
My daughter bumps into her Aunty across town etc, and is civil towards her and even mentioned to her about her account sharing the same name. Aunty said “Well that is how I introduce myself to people, I am thinking of legally changing my name as I really like your name”. (BS)
My SIL has no part in my children’s lives, and vice versa.
Just today i met someone who said “I had no idea you had married children and were a Nanni, I saw the pic of your grand daughter on your daughters FB page”.
Me.“What are you talking about? My children are ABCD, the ones you have met.”
Her, " No , I saw it on so and so’s page."
Me, " THAT is not my daughter, that is my SIL who thinks she shares the same name as my daughter".
I’ve told my daughter to close down her account. Her point is, why should she have to close her account. Should she close her account and re open another, what name should MY daughter use, since she cannot use her own name.
I’d appreciate helpful advice, if any.
Thanks.
B/C the main profile pic shows up to when someone searches for namse on FB. Not sure how anyone can choose the aunt after seeing your daughter’s face pic on her profile. And from now on, whenever your daughter meets new people, if FB/keeping in touch comes up during the conversation, your daughter should specifically ask them to search for her using her e-mail address and say something like “Surprisingly there is another person who has the same exact name and it causes confusion. Please search for me by using my e-mail address.”