I would say it is technically possible as both flights are on KE. But lots of things need to go her way. No delays incoming, no delays deplaning, no delays at the transfer desk.

I would inform the KE staff upon checking in at JFK that she is transferring so hopefully the KE staff can assist the second she lands at ICN.

I have done it before and transferred quickly and easily within minutes of arriving. I suggest that she get to the transfer desk as soon as possible as the transfer area can become a bottleneck if many people are going at the same time.

You were allowed to purchase the ticket with this short of a window for transfer?