I797 expired but have valid H1B and I-94

[Mgup]

Hi ,

My wife is valid H1B and I-94 until July 2018, but her I797 expired as she was on maternity leave 

1. Is there any issue if i-797 got expired? Is she out of status?

2. Now she finds another employer who is extending her H1B. Will it create any problem in H1B extension/H1B transfer?

Thanks a lot

[xTDx]

How did  I797 expired as she was on maternity leave  ? How does being on maternity leave gets 797 expired ? Was she laid off ?

Please provide complete details. It seems to me that she might be out of status if 797 is not active.