First, we would spoil a lot of presents if we shared account credentials :D
Second, because of how the feature has changed over time, her account wasn't 'upgraded' to the top level that they defined when they first redid the system. She got all the benefits still. Now, as part of this newest shakeup, they determined her account to be invalid and ending the membership for it. Her brother's account, because I added it later in the newer system, was labeled as the full featured adult account. Last time I tried to change this they wanted to charge me money, a whole new membership worth to change it, but I didn't push it as she had the benefits still.