It's a mistake.
On JKR's old website it states;
Interviewer : At the end of 'Goblet of Fire', in which order should
Harry's parents have come out of the wand?
JKR : Lily first, then James. That’s how it appears in my original
manuscript but we were under enormous pressure to edit it very fast
and my American editor thought that was the wrong way around, and he
is so good at catching small errors I changed it without thinking,
then realised it had been right in the first place. We were all very
sleep-deprived at the time.
This was corrected in later editions (as well as some slightly amended text being added).
In my US (2013) ebook version, it clearly states :
And now another head was emerging from the tip of Voldemort’s wand …
and Harry knew when he saw it who it would be … he knew, as though he
had expected it from the moment when Cedric had appeared from the wand
… knew, because the woman appearing was the one he’d thought of more
than any other tonight … The smoky shadow of a young woman with long
hair fell to the ground as Bertha had done, straightened up, and
looked at him … and Harry, his arms shaking madly now, looked back
into the ghostly face of his mother.
‘Your father’s coming …’ she said quietly. ‘He wants to see you … it
will be all right … hold on …’ And he came … first his head, then his
body … tall and untidy-haired like Harry, the smoky, shadowy form of
James Potter blossomed from the end of Voldemort’s wand, fell to the
ground, and straightened like his wife.