There is a league in Fullerton/Palencia . I have never found a website for it. It's called Orange county community youth soccer league. They have no girls team . The girls play with boys , they are allowed to be one or two years older in the age group they play in.I think after 14 years its not a good idea for girls to play with boys team, just my personal opinion.
The office is at 465 w. Valencia Dr. in Fullerton , towards the back. I know they are open on Saturday for registration . My son's teammate father told me about, I would have never found it myself. Its40 dollars for the whole year plus you chip in for ref fees . So teams are good and some are bad