Does the Jamaica lirr station have an elevator at the platform? I only see escalolaters.

Yes,Elevator on every platform. The Elevator is directly behind the Staircase. Behind the Escalator is the Staircase, behind the Staircase is the Elevator. Hope this helps.

You need to take an elevator UP from the platform to an overpass, then DOWN to exit the station.

Escalators and elevators should be right next to each other

There are elevators.