I don't think it's sleeping pills. In the tweet where she gave the $15K number, it sounds like she had a plan to move up merch sales to make up for any losses. And I doubt she would have to make up the losses right away, because even if the cover was released and monetized there would still be a few months delay from Youtube in regards to payouts. And I seriously doubt that Niji "2%" sanji is paying out cash advances to their talents for monetized covers. Hell, she probably wouldn't even see her cut until April.
Her parents abusing her for not spending $15K on them is something I would believe. The timing fits because of the Holiday, and it's not like she would have to go to the hospital for that, the tweet could be a lie to get everyone off of her back while they dish out Asian Parent Discipline.
But don't hospitals also place patients under observation if there's a good chance that complications may arise from a procedure? If she actually did have an accident, she may have hit her head hard enough for Doctors to believe that complications or brain bleeding may occur.
Manager skinwalking for a stealth suspension would unironically be the best possibility.