VisCyanicmy family thinks my sister is a lesbian and seeing how its destroying my mum makes me glad i never told her i was gay :/Your sister is almost certainly not lesbian if you are gay. There is a tendency that every younger brother has a ~1% higher chance of being gay, so if your sister is younger than you, she is most probably also attracted to men.
she is younger than me but i'm not sure i understand what you're describing, could you elaborate?