I found out my younger sister is a lesbian, should I tell our parents?

A lady has narrated how she discovered that her beautiful younger sister is a lesbian but is in dilemma on whether to tell their parents or not.

Read her story below and give her suggestions in the comment section.

I just got home from school, i noticed that my younger sister of about 18 is acting creepy these days. At first i didn’t take it serious cause i was thinking maybe all these small boys have started asking her out and stuffs, because she is extremely beautiful, not trying to exaggerate but trust me on this one, so i had to calm down until one day we were all at home with other siblings, she told me she would be having visitor, before i knew it, she started sweeping everywhere, took her bath, sprayed perfume, i was like who is this small boy that that my sister is doing all these for. 

I was shocked to see a girl knocking on our gate. Jeez!!, worse part is that the girl is a TOMBOY, from there i concluded my sister is Lesbian. 

Just this morning i had the opportunity to check her phone while she was bathing, what i saw there brought tears to my eyes… Now i can’t even look at her, I don’t know if i should tell my parents, cos we get along very well and i don’t know if revealing this will cause problems in our family, my family is well known in the church, what if this get out to people??.. damn!! i don’t even know what to type again.