Spouse's H4 stamp duration with I have two H1B jobs with different durations

[Tron]

I work as a research scientist for a university and for a big company on two separate H1B visas (full time at one, and part time at the other) sponsored by them. My wife was previously in the US on F1 and H1B status when we met, and she returned to her home country shortly before our marriage.

She reentered the US in B1/B2, we got married here, and she got a change of status to H4. Her H4 status in the US is valid until the end of 2012, which coincides with one of my H1B approvals (full time job) and my H1B visa stamp. My other H1B status (part time job) is valid until 2014, but my wife was not added as a dependent in this visa application.

My wife is traveling outside the US, and will get a H4 visa stamp in the home country and return to the US. Can she only use her current H4 status approval and get a H4 visa stamp until 2012, or can she show my other I-797 approval and get a visa stamp until 2014?

Thanks in advance!