However, her two takeaways from her experience are, "your skills will speak louder than your gender," and, "to become a female developer, you only have to do what any other smart dev would do...[i.e. work hard]." I think the problem is precisely that many women have found these statements to be false. Many women that are smart devs have gone into the tech sector with good skills, but found that they are still judged unfairly by their gender. The fact that this women hasn't experienced that doesn't mean the problem doesn't exist for others.
Also, the claim that if you work hard and have good skills, then your gender won't matter has the (probably unintended) implication that if you do find others discriminating against your based on your gender, then you must not have the skills or the work ethic.
I really don't know to what extent gender discrimination exists in the tech sector, but I think we should be careful to avoid over generalizing from individual experiences and we should be especially careful not to suggest that discrimination only happens to the developers whose skills aren't good enough to overcome other people's stereotypes.