Connecting flight help needed

[gazingatgoats]

My DD is flying from the UK to the U.S. next month and needs some well travelled person to explain how connecting flights work. She will fly into JFK New York and then get a connecting flight to Portland, Maine. The problem is there is only 2 hours between arrival time and departure of the connecting flight.
We have no idea what she needs to do when her first flight arrives re immigration and luggage and I'm now panicking that 2 hours isn't long enough and she will miss her connection.
The flights are all with the same airline and I know they will put her on the next flight if there is a delay, but the next flight with that airline is not until the following day.
I would really appreciate any advice or anyone with experience of flight connections. Thank you

@gazingatgoats Have you looked into a later flight to Portland? If the first flight is late it's going to be stressful.

Usual in the USA as no such thing as transit there

I had a terrible experiece getting a connecting flight through JFK, the queues at immigration were huge and just didnt move. After two hours we had barely moved. We only made our flight (and with only minutes to spare as flight had nearly finished boarding) after me several times leaving the queue to go to the front and beg staff to let us get to the front to make our flight and on my 3rd attempt they relented and let us go ahead. I very much hope that is not the expereicne your daughter will have. Just tell her to be be quick off her flight, mindful of the time and if needs be, be assertive if looks like she wont make her flight. As stated above yes you have to get your bags too.

Thank you @Onthegrid Will tell her to pass as many people as possible, she loves a challenge! And thanks for the tip about the paperwork, she is very organised and has a clear folder for it already