b2 visa extension

Hi,

My mom's 6 month visa and I94 is expiring in Aug. I want to extend it by couple of months as she is not well enough to fly and undergoing medical treatment.

Regarding her extension I have a question while filling the I-539.

I have changed my employer recently and my H1b application with my current employer is not yet approved.

What shall I fill in about my employment details.

Shall I give my old employer details for which I have approved visa and I797 or do I give my present employer details?

If I give my present employer's details will the H1b receipt number suffice?

Thanks!

Deb