I94 expring - H4 to H1 in process

[thalaivar]

Hi,

I could not find this question asked before. Here is my problem -

My wife is on H4 and her I94 is expiring in Aug 2013. An employer is filing her H1B in April 2013. Assuming H1B gets approved she will be eligible for work from 1st October 2013. However her current I94 is only until Aug 2013. She is not planning to travel until October. What should I do to get her I94 extended? Will the H1B be in jeopardy if I ask for I94 extension (on H4) after April?

Regards

Thalaivar