It's an entrance directly facing the road and with the sign showing that it leads to the mall, should be able to see from the driveway already. Note that that being part of the loading bay, the doorway would be above street level, up a couple of steps.
Tell her it's waiting while queuing, cannot move from that corridor until the incoming train passengers have alighted and exited. Walk walk to SG immigration, long walk to JB immigration and customs clearance, then board. No photo taking on the platform otherwise tio officer scold coz already got signs around.
Coming back, queue for up to half an hour. Clear eGates, go down clear MY immigration, then the fun starts, like train to Busan coz many tend to rush to get a seat (for the FIVE mins ride). The queue waiting to board will be from 2 directions, but they'll be people just sitting around bochap just squeeze once the doors open.
Reach SG have to enter macam

communal feeding station via an eGate. After immigration clearance, out another eGate and head to the customs clearance. Then walk walk to the lao kok kok lift to get to the ground floor otherwise walk down the stairs.
Then walk to the bus stop or Grab/cab just outside.
Worth the 5 mins ride?