You may also qualify for an O visa, which does not require fulfillment of the residence requirement. If you function at that level, that's your best option. My sister has unsuccessfully petitioned for permanent residency through her work as a physician. Now her working permit has expired for two years. She might be better off applying for cancellation of removal once she's here for ten years total.
Cancellation of removal is only available in removal, better known as deportation proceedings.
Hardship to herself is not enough. If she marries a US citizen, then she could get a green card without departing the US, and without removal and cancellation of removal. Otherwise she's out of luck. She is a Hepatitis B carrier. Sana Loue, the person who wrote the book on the subject of medical waivers doesn't practice law anymore.