<human>: Summarize the given text in a few sentences.

As I said I am 28 and my baby sister is 23. We've always had a really good relationship despite being completely different people. Now, a lot of bad things happened to her, but honestly from what I see she grew up to be a completely normal, rational adult, and I've seen people who have been through less handle it very poorly. 

A few days ago I overheard her talking to someone and despite every fiber in my body telling me not to stick my nose where it doesn't belong I did it anyway. I really wish I didn't. I heard something that broke my heart.

Apparently she is again the only one in her group of friends that's not in a relationship, I think she was half crying but I heard her say something how none of the things that are happening to girls her age, are happening to her. I might have heard it wrong but I think it was something along those lines. And then I heard her ask, now full blow crying, ''what's wrong with me?''. Here's the thing, my sister is a happy person, despite all the crap she had to go through she's the strongest person I know, but I have never in my life heard her talk with so much pain and anger in her voice. It honestly scared me. It was like listening to a total stranger. 

We're sister, so naturally we talk about everything. Two years ago she was in her first ever relationship, but she lasted 4 months and was miserable the whole time. That was her first and only relationship. We talk about boys all the time but I have never heard her say she liked someone. And she's not gay, or assexual. 

I have no idea how to approach this subject, first off all she's not gonna be happy about me listening to her private conversation. But I need to to something. I wish I could describe to you the pain in her voice. I had no idea she felt that way, I have to do something to make it less painful, she's my baby sis and I can't stand knowing she's suffering. 

So Reddit, what do I do now?
<bot>: Heard my sister talking to someone, turns out she thinks she's unloveable and I have no idea how to fix it