Female solidarity doesn't really exist because most of us are socialized with a competition mindset, or actually have experienced mistreatment and snake behavior from other women in the past so are extra on-guard. I've had multiple female lie to me that we were friends then go behind my back spreading gossip for clout. I also suffered from being raised by a pickme mother that put a lot of shitty ideas in my head. Until I found feminism I definitely would've viewed your sister with polite suspicion at best