Hi,
It's very simple, but first I suggest increasing brightness and disabling shaders for at least one night, this way, you'll clearly see the whole scene that you can interact with.
Now, if you fully take off her blanket, it ends up in the bottom right corner of the bed, when clicked again, a bar minigame pops up and if successfully you'll cover her up as it was at the start, same thing goes for other clothing items, but they end up on the left side of the bed, by increasing brightness you'll see exactly where each piece of clothing is
Cheers