Travel to India and come back on H4 while an employer is filing H1b

We are planning to travel to India on the second week of May and come back on June 1st week. An employer is filing H1b for my wife (who is in H4 now) . Can we travel to India during this time frame? as the H1b approval information will get only by late September.

Since she is in a status (H4) currently, her employer might have filed COS(Change of Status) petition from H4 to H1. Once she gets out of the country, she will have NO status(status is applicable only while one is in United States only).
So, Technically, her COS petition is invalid when she leaves the country. Thus, as per the USICS rules, the H1 petition should be rejected at that point of time.
But practically, it may not happen(again, legally, it should be rejected) as she would be back shortly onto H4 visa once she enters back into US. Its a gray area, slight chances are there to be dropped into the other end, if luck is not on your side.

Thanks for your update.