Need one advice - my H1B was approved earlier till March 2020 nd my wife got her H4 Stamped , came to US Nd went back .
Later in the amendment it’s changed to May 2019 Nd. Now my extension is ongoing so can my wife travel now to come to US before my approval as her H4 is valid till 2020??
Well, even though she has valid H4 visa, if asked at Port of entry, she would need to show the copy if I-797 approval notice of the spouse that is valid and currently used. So, in your case, your amendment changed it and now you are in extension with receipt. The better thing to do is to get H1B approved, that is applied as extension and carry the same and re-enter US. This is to avoid any issues at port of entry.