If she has this visa does she still need the ESTA visa?
No, the ESTA is only for visitors travelling visa-free under the Visa Waiver Program.
When she is on the plane, she will need to make sure she gets a white I-94 landing card from one of the attendants (they will pass them round during the flight) and she will need to fill it in for going through immigration. She must keep it with her passport while she is in the US, and then hand it back when she leaves the country.
Also, whatever she does, she MUST carry her DS-2019 form along with her passport and visa when she goes through immigration... she cannot enter the US on her visa without it!!
When I travelled on my J1, I didn't realise this and packed the DS-2019 in my suitcase... when I told the immigration officers, they detained me in a room for 2 hours and then escorted me to baggage claim to retrieve the form - I nearly didn't get into the country.
My brother went one step further last year, and forgot to bring his DS-2019 altogether (even though it was his second J1 and he should have known better). He was almost not allowed into the US, but the IO kindly stamped him in for 30 days with the caveat that he had to produce the DS-2019 to US immigration before the 30 days were up, otherwise he would be sent home.
Unfortunately my mum sent it to him via Royal Mail Airsure.... and surprise, surprise, it never arrived. He had to contact Washington with an urgent request for them to reissue his DS-2019... which arrived exactly 1 day before his 30 days were up!
It's really not worth the stress of not having it with you!
