H4 and H4 EAD with H1B extension (currently on F1)

MY wife had H4 visa stamped until July 2024. She went to India and got her F1 visa stamped in Aug 2023 so I assume her H4 visa is discontinued.
My H1B will expire in July 2024 and I am planning to apply for H1B extension , COS from F1 to H4 and H4 EAD as concurrent filing in premium processing. If it all approve din 15 days does my wife H4 and EAd start from moth of July or it would start from the day of approval? if it starts from July then will she be in F1 until then? if yes then how would we maintain the status until July. in this case we would still need to request F1 OPT EAD even though h4 is already approved from july 2024.
Can anyone help me answer these questions?

Check her passport and see if the H4 visa has annotation/stamp thar says canceled without prejudice. Otherwise it stays valid.

Status will change to H4 the day it is approved or the start date on the approval notice if you requested a specific future start date while filing form I-539.