Type 1 diabetes...

My cousin who has been a type 1 diabetic her whole life, stopped taking her insulin and says she's 'self-medicating'. Just wth does that mean? From my research, type 1s bodies can NOT make their own insulin. I've been reading on young type 1s who can not afford their insulin anymore and dying. Is it possible for a type one diabetic to have such a strict diet that they do not make any glucose at all?