She is a disciple of a small nearby Sect, and her Master is the Sect Leader, who only has a Golden Core cultivation... not even qualified to receive the summoning order from the Five Sects.
There was no need for them to come.
But the Nascent Soul Sect they were attached to received the summoning order and, after much thought, not wanting to put their own disciples at risk, brought them along as part of their own disciples.
All the way there, her Master kept complaining, feeling like cannon fodder, fearing that the Demon Sect would annihilate them completely, ending the lineage of their Founder.
But Fang Yuan seemed a bit heartless and carefree—she actually cried twice before departure, terribly afraid, but once they set off, she simply adopted a devil-may-care attitude, adjusting her mindset.
All she thought about before dying was to see more of the world, hence she still had the energy to look around.
Every tunneling light in the sky was a Nascent Soul True Master.