You will need the User ID and Password that was used to create the 2021 TurboTax online account. Ask your roommate for this information.
To access your prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/
ask her. it is doubtful that under any conditions Turbotax will allow you to access her account. if she used 1 account for your and her returns only the last one prepared is still there. the other is permanently gone.
if you can't get it from her, you can get a transcript from the IRS either by registering to get it online or filing 4506-T for a transcript or 4506 for a copy of the return.
https://www.irs.gov/individuals/get-transcript online transcript
https://www.irs.gov/pub/irs-pdf/f4506t.pdf IRS sends transcript thru mail free
https://www.irs.gov/pub/irs-pdf/f4506.pdf IRS sends you a copy thru the mail for $43.