Yeah, my parents keep track of me too. They ask how my studies are going and how I'm doing. They don't stare at me through webcam while I sleep.
Her parents don't own her. She is an adult. They decided to pay for her which is their own choice. They could have stopped any time, so holding the "we paid for her" over her head is kind of weak don't you think?
As for you getting a nursing degree in 30k, that's actually pretty cheap. I'm sure you got aid and what not? A lot of people (including me) don't qualify for need based financial aid. I do agree with the viability of the degree being low in terms of future job prospects....but that's another discussion.