I-485 and spouse Visa

[chunu]

My I-140 is approved and I will be filing I-485 by next month.
My wife is currently working on H1-B, but she is pregnant and will be
leaving the job in 1-2 months. I am little confused on what we should
do now. Can you please suggest out of following 2 options.

- She can file I-539 ( Change status back to H4 from H1-B) now...continue
working with the current company for 1-2 months. Meanwhile my I-485 will
be filed and she will get the EAD with 3-4 months. Then after the baby
is born she can still work on EAD and maintain her status with H4.

- Continue working on H1-B for another 1-2 months...then take unpaid leave.
Meanwhile my I-485 will be filed and she will get the EAD. Then after
the baby is born she can work for any Company. What will be her status
if she no longer works for company who is holding the H1.

Please help. I have some more questions.

- Can we file I-539 for my wife after filing I-485.
- Can we file I-485 while I-539 is pending with INS.

Any help will be greatly appreciated.