I have a question about the labor laws in Arkansas. My daughter, who is twenty years old started working at a job part time several years ago when she was still in school. She went to a technical school as well and graduated but still wanted to stay at the same job. As she was out of school her employer has increased her to 40+ hours a week and she was told she was full time. Now after working over 40 hours a week for over 7 months her employer is saying she is part time. My understanding of this was that if you worked at a job for over 90 days at 40 or more hours a week you were full time. Since this affects whether she gets her vacation time I would appreciate any help or advice on this matter.

The problem with that assumption is your definition of "full time". What one company considers full time another may not. For example, some firms consider full time for any employee who works 35+ hours. What matters here is the company's definition of "full time". If the company defines "full time" as regularly working 40 hours, then you daughter may have a case for having her status changed to full time.

If the company has "purposely" not changed her status in order to deny her benefits then that may be an issue. By benefits I mean participating in a company offered health or medical insurance program(s), 401(k), etc.

CBG does the same apply to PTO?

http://www.state.ar.us/labor/divisions/labor_standards_guide.html

For the most part PTO and vacation plans are not generally ERISA plans, so no, generally that would not be the case for them.

BTW, there are only two states that ever determine what is considered full time by law, and even in those states there are exceptions. Arkansas is neither of these states. There is no law I know of in any state with the possible, and only possible, exception of those two that guarantees full time status after 90 days, regardless of how many hours were worked.