I-539 to file change of status from H1 to H4 & H4 extension of minor

Hi, my husband’s H1 extension approval came few days back, now I am applying for my change of status from H1 to H4 using I-539 form by selecting the option 2.a. “A change of status” in Part 2 “Application Type” . Can I apply for extension of status for my minor son’s existing H4 status in the same form giving his details in “Supplement A”? OR

I need to submit a separate form for him selecting the option 1. “An extension of stay in my current status” in Part 2 Application Type and filling his details.

If needed to file two forms I have below doubts:

Do I need to send two separate checks of $370 each to DHS with my form and my son’s form?

My son can’t sign the form as he is minor child, so who and in which fields can sign the form?

My son’s I94 was issued with his old passport number and we renewed it last year, so which passport information I need to give in the form for the fields 11.b, 11.d & 11.e and how do i give new passport details?

Do I need to give any supporting documents of mine for his application or only his father’s H1B extension and pay stubs copies are enough?


Could you please let me know whether you filed in a singe application or two applications for I539