H4 Visa and Entry into US with 2 months left in H1B

Hi,

My H1B is valid until end of July’18 and my wife is planning to travel India in May’18. Would she be able to attend the H4 visa in end of May that is with only 2 months left on my H1B.

She is planning to come back by end of June’18 or 1st week of July’18. Would she be fine to comeback into US with only 1 month left on the visa or will she face any issue at POE.

I think i will be filing my extension by then but not sure if I could get the approval by then.

Any suggestions would be appreciated,

Thanks!!