y H1-B extension is approved and My wife's H4 & H4-EAD is in pending status. But my wife applied for H1-B which is approved for 2020 CAP

[AmarG]

Hello Experts - My H1-B and my wife’s H4/H4-EAD stamped until Sep 09 2019 (Expired now). However, My H1-B is renewed till March 2022 via premium, but  
My wife’s H4 & H4-EAD petition is still under process (received appointment notice for bio metrics). And she applied for H1-B (2020 CAP) in April,
and it is approved till Dec'31 2019 (her H1-B status will start from Oct 01, 2019).

Isuue.
1) If her H4 and H4-EAD approves before her H1-B expiry date (Dec'31 2019), What status will she be applicable? (Will her status change from H1-B to H4 automatically?)

2) Let's say if she doesn't apply for H1-B extension and her H4/ H4-EAD is still under process/ approved after Dec 2019, will she be continued to stay on H4 status legally?

3) Is there a way can we check whether her H1-B started from Oct 01, 2019? 

[pontevecchio]

Have her ask the employer for the approval notice.