I 539 application for H4 status

[vt1979]

My H1B is valid till 09/08/2016. My employer is applying for the extension of my H-1B from 09/09/2016 to 09/08/2019. My wife is currently on H1B and would like to change the status to H4 from 04/01/2016. Can I attach her I 539 (H1B to H4) for the time period 04/01/2016 to 09/08/2019 with my H1B extension application?
Or do I need two I 539 applications for the time periods (1) 4/1/2016 to 9/8/2016 and (2) 9/9/2016 to 9/8/2019?
Any help will greatly help me out. Thanks in Advance