There isnt just one " main line " of the sicilian(s).
siclian main line?

phhh, what do girls know about chess anyway :P
lol very true...and maybe that is the main line for one specific variation. For instance, there is a mainline Dragon and a main line Accelerated Dragon. There is a Dragon, Yugoslav Attack, Soltis Line. Trust me, there are tons of main lines in the Dragon.

That is the four knights variation. It is hardly a mainline by any standard as it is much less popular and slightly worse than most of the other open sicilian systems.
Of course there are many mainlines in the sicilian, but if I had to pick a "mainline" for the whole sicilian it would be the Najdorf, and if it had to be a certain variation within the Najdorf it would probably be 6.Bg5.
well at the jerry hanken tournament, this girl i was facing for fun after the tournament said that e4 c5 nf3 nc6 d4 cxd4 nxd4 nf6 nc3 e6 was the main line for the sicilian. i dont think there is a main line for the entire sicilian but she thought otherwise. is that the main line?