I am very happy to hear that children raised by lesbians do well, as I'm all in favor of people being able to raise children. It is a useful study in showing that these kids aren't disadvantaged and that therefore we should be ok with lesbians raising kids. I doubt anyone that doesn't believe that already is going to be convinced otherwise, but still, yay. My issue is that the scientist is speculating that the parenting is responsible for her findings, when in fact the study did not show that. In retrospect, at least the author is clearly speculating, and the journalist didn't report those speculations as fact, so perhaps I shouldn't complain.

The variation in IQ is something like 70% heritable by adulthood, so yes, it is entirely possible that lesbians have genes associated with confidence and high academic performance. It is a legitimate alternate hypothesis, if a politically incorrect one. It's also entirely possible that the scientists is right and that parenting practices are responsible, but I find that to be unlikely, since studies of adopted children show that they strongly resemble their birth parents and their personality and IQ are uncorrelated with that of the people who raised them.

Every science article ever ends with the author talking about their next study. They do this for a few reasons: one, because scientists always wish they could do bigger and better studies than they have budgets for; two, because doing studies is what they do for a living, and three, because if you don't do more studies you don't get any grant money and you either don't get paid or have to deign to teach classes.