Search Results: get over cheating

I fell in love with a total sham once; someone that never existed. He played that role for years.

Honestly which heartbreak or love deception would you rather deal with?
A) Getting cheated on or finding out they love someone else
- They once had feelings for you but things happened and they cheated on you. Or they loved you but at the same time can't get over an ex partner who they also love. This is obviously the common scenario many people deal with.

B) Finding out they can't love anyone at all
- They never had real feelings for you (they have zero to little ability to love) or if they did, they saw you as a commodity to get something. They forged a complete relationship and kept the act going for years. They aren't even a normal human.

She's always been slightly different but seems to get along with everyone overall. Things I'm noticing that's making me question her (she just turned 19 last month):

- She just broke up with her long-term boyfriend and the following day was partying. She blocked him and claims to have already gotten over him.
- She hardly ever cries during funerals, even when our grandma passed away last year.
- She cheated on a boyfriend once and claims to not understand at all why cheating is a big deal nor why people get so ''worked up'' about it. In private she admitted to me that she really felt no guilt nor remorse for cheating.
- She always seems excessively happy (too much) and rarely ever gets upset.
- Her self-esteem is over the top. She likes talking about herself and achievements so much. Sometimes it's excessive. I understand you gotta love yourself but her way is too much.
- She always made friends easily as a kid and had no issues finding new ones if she had a big fallout. She treated them the same as her recent break-up, didn't miss them either.
- She once said to me ''I'll get someone rich one day. I always get what I want.''

My parents and others just think she's special and can get over break-ups so fast. I think not. Is there something wrong with my sister? Is she a normal person?