I was recently added to my Mother's 16yo Citi/Sears card and it took until an entire billing cycle went by before it went on my reports. So my best guess is to just be patient until August 24th.
I got this answer from one of the managers that is over Myfico. Authorized user accounts will no longer be factored into the algorithm that makes up the score. Other than that you can ask your sister when the billing cycle or staement date ends. Within a few days after that your credit report would be updated.
That is correct. This came from a manager that is over MYFICO and has worked for Fair Isaac for over 22 years. The authorized user accounts have been abused. It's not fair to someone that actually owns their own account or has been cosigned for. They have demonstrated financially responsibility, through their actions, by making payments on time. The AU is just piggybacking the information off of another individual's credit report. The lenders and FICO score have no way of measuring what level of credit risk that the person is. And the FICO score has to be earned. It can not just be handed out.
This appears to be a repetition of several years ago when FICO preliminarily announced that it was discontinuing inclusion of AUs in their scoring.
That "decisions" was later reversed, apparently in view of concerns over possible violations of ECOA when the AUs were of a stay at home spouse.
I would like to see a clear announcement from Fair Isaac as to their official policy before accepting as a final decision.