New H4 stamping required if primary petitioner changes employer

[chiru87]

I am Primary petitioner having a valid H1B, I have changed my employer recently (I-797 received for me alone from new employer). My wife have H4 stamped with my previous employer (I-797), but she never traveled to USA. Now that she wants to travel to USA, is the current stamping from previous employer is enough if it is expires 4 months from now or should she go for stamping again?

Thanks for your help.