I-140 approved/Spouse on F1

[seshueceng]

Hi,
I know many people might have asked same question but I did not get clear answer from anywhere.

I have my I-140 approved and waiting for date to apply I-485.

My wife has got admission and planning to get into F1.
My question is will she be eligible to be added in my I-485 process when it opens up if on F1?
Or she has to stay on H4?

Please suggest since I ont want her to fell in status issues later.

Thanks,