She will almost definitely arrive at D6, one of the "bus gates" (in other words she will be bussed to the terminal from a remote stand). From there it's up one flight of stairs, then a very short walk to the main concourse where she turns left to go through passport control and security for the Schengen part of the airport.
Once she is on the Schengen side she will probably have a fairly long walk to B or C Pier (there are moving walkways for some of it), or if she is lucky she may be departing from the Schengen part of D Pier which is much closer.