Use the hints function under settings, NOT THE "?" one.
There's three times you need to be choosing clothes, I believe at 7, 17, and 18.
So at 7 am, go to your studio and select the first clothes on the left. Still at 7, go to her room and put the clothes on her mannequin. Then continue on with your day (you should be making breakfast for her next).
At 17, do the same. Go to your studio, select the first clothes on the left, then go to her room and put the clothes on her mannequin.
At 18, again, the same exact steps, then go to dinner with her.
It's very weird because she's already wearing the clothes you pick out for her at first, so it's confusing on what to pick. On top of that, New Bob mentions that he should choose something less revealing, despite it being the correct choice.
This episode sucked, honestly.