She felt isolated, alone, unseen, unappreciated, and unable to teach others. These feelings have less to do with being a woman in tech, and more to do with her own social habits and communication skills.
If she felt alone and isolated, why didn't she socialize with her teammates more? Organize some social events to bring everyone together? If she felt so isolated, what was she doing to address that? Was she isolating herself?
Becoming an effective manager isn't easy or automatic. For someone to learn from you, you need to first develop mutual trust and respect, and that can take time. I certainly have worked for people I wasn't willing to learn from, and that had nothing to do with their gender. I didn't respect them or trust them as a mentor. It sounds like she resented her struggle to be a lead, and blamed it on sexism rather than work on communication skills to learn how to be an effective mentor.
The only sexism here seems to be her viewpoint of the men around her as unloved, unseen, and needy for female attention. If she treated her coworkers that way, or felt the need to distance herself because of this perspective, that might explain why she felt isolated.
Sometimes when we're insecure about something, it makes us more brittle and sensitive. This can make it difficult to be comfortable around others.