h1B spouse plan to apply 485 . h4 spouse plan to apply later because no birth certifi

[kannan alpadi]

i am an h1 b valid until april 30 2016. my wife is on h4 valid until april 30 2016.
my i-140 approved recetly. i plan to apply for my I 485 but not for my spouse because her birth certificate is not available. It will be avilable in 2 months.

if i apply 485 and got approved. whether she will be allowed to stay here on H4 until april 30 2016.

pls advise