She seemed fine, having her get used the controlls builds tension, almost mirrored Luke's -they're coming to fast, struggle with it at first, then getting to the point where she yell's I got one! (almost exactly) one to one mirrored Luke's scene, and youthful enthusiasm, which is what they were looking to callously imitate.
By the end she was then the one giving the cues, and then driving the ship too, and proficient at it all.
It had nothing to do with fear she was a Marysue, and more to do with them just wanting to recreate the Falcon vs TIE moment down to Luke's enthusiasm, (weather it fits her character or not), cause they are bereft of ideas.
The only thing missing was the fussy protocol spouting droid getting knocked out of commission, . ...Oh, wait.