H4 Child I 94 extention

[Sree Raju]

Hi, 

I have a valid H1B until 12th April 2018. When my Child came to US, her I 94 was issued upto 12/12/2017 as her passport was valid until this date. My wife and I have I 94 valid until April 2018

My employer applied for my H1B extension, and I 539 for my family, with validity start date from 13th April 2018. (now pending adjudication)  

My question is, will my daughter's I 94 get extended automatically until the validity of H1B extension or do we need to apply a separate I 539 for her , for the period 12/13/2017 through 04/12/2018?