Question about H1B and H4 and legal stay in US

My employer has filled my H1B(filling date 7th Jun). Similarly my wife’s employer has filled her H1B(filling date 7th Jun). Currently she is working on L2 EAD and depend on my L1 visa. Both of our visas valid till 4th Nov 2012.

1. If my H1B gets approved first than her in that case do you think she can still be on L2 EAD or at least can stay in country.

2. After my H1B approval, let assume her L2 visa is not valid, in that case will I get enough time to fill her H4 without sending her out of country ?

3. Just to be vigilant, Can I fill her H4 right way to ensure I have a back-up for her. Will this has any impact on filled H1B petition of her. 

Any help highly appraociated