This has been bothering me for awhile, because I feel like this case is super specific. So one of my parents used to work at SLAC National Accelerator Laboratory (a department/division at Stanford), but doesn’t work there anymore (don’t want to disclose any more information than necessary). I’ve read some past discussions about having a connection this may gain another read of your application/advantage. Because my parent doesn’t work there anymore, would this “advantage” still apply? Wrote my app everything, but wondering if it’s still even worth applying to… I feel so unqualified. Thanks in advance 
I understand the desire to squeeze out any advantage but your parents’ connection won’t be of benefit to you as an applicant.
^^ Agree. If you are feeling “so unqualified” even being a true legacy wouldn’t help. A former affiliation won’t do anything for you, unfortunately. Apply though if you have the time and the money and hope for the best. Good luck!