I don't know if this is still in place but when I started working part time if you worked so many weeks in a row of 40+ hours you were automatically turned full time. That happened to me, right out of training I was given over 40 hours a week and I believe it was 13 weeks later the company had to change my status. In my department they only reviewed people twice a year for full time status.
I was able to work and support myself and a condo mortgage (in FL) on my Disney salary. It was something I would not have traded for the world!