H4 Extension Questions

[Happygolucky26]

Hi All,

I transferred my H1B from employer A to employer B. I got the approval 4 weeks ago. H4 of my wife and kid is still with the employer A and is valid till 09/30/2013.

Are my dependents required to file for a transfer or extension of their H4s because I have transfererd to a new employer. If yes, would it be a transfer or extension. Form I-539 only mentions extension of status.

My H1 is valid till 2014. Can my dependents file for extension till 2014 or it will be rejected because they have enough time left on their curerent status.