Just to add: I don't think she is dumb. There must be some self-saboteur in her that doesn't fully believe she deserves all this (which she does). Goes along with why she talks herself up so much cause maybe a lot of what she's experienced in early life has tried to teach her she's worthless or something. Like her mom abandoning her or even here people calling her ghetto just cause of her nails, her hair or accent. And now thinking this confirms it. Anyway, she may think this is just two-bit psychology but it could be legit.
That NY Times piece says you only have to test free of cannabis on the day of competition so she could've waited a couple days.