Is it possible for us to hire an HR generalist on a temporary basis? We've had mis-hires before and want to try her before we hire her.
Absolutely, it is fine to hire someone temporarily on a contract basis. By doing so, you could treat her as an independent contractor or a short-term employee. Be sure to provide an engagement letter discussing the scope of the engagement, the length of the project, the work expected, the pay rate, and, importantly, include your "at-will" language specifying that the engagement does not constitute an employment contract and can be severed "at-will" by either party without notice or cause.