Well to be fair, in the second game it probably wasn't so much of an issue...

But maybe they had multiples of the same outfit on hand...though there weren't any wardrobes either...but there -were- swimsuits in the supermarket. Maybe there were other clothes too.

(But yeah. That'll be her first clue that something's up. Where's the bat??? Why brown? That is Hope's Peak brown even though she only has Twilight Syndrome to clue her in...)