H1B transfer while H4 and H4-EAD applications are pending

My H1B was approved recently. My wife’s H4 and H4-EAD applications were submitted along with my H1 in Jan, but they are still pending. We have got H4 biometric appointment next week.
I’m thinking about changing employer in the next few weeks. What happens to my wife’s current H4 and EAD applications? Do I have to file H4 and wait for biometric again? I’m not sure if H4 will be approved before I transfer H1 to new employer and my current employer revokes the H1. Is it advisable to transfer after H4 is approved? Can EAD be delayed because of this? Thanks.