You can't fix someone's perspective

Hey there. So, I’m wondering how I can help my sister with her self esteem. She’s very beautiful, and it’s been made clear to her by many that she is, but at the end of the day she thinks herself ugly. I get really frustrated and angry with her sometimes when she does this– it’s so clear that she’s lovely, everyone knows, and it’s obvious she is. I just don’t know what to do. I want her to see how great she is, without hurting her.
realsocialskills said:
It’s hard for me to tell from your message how your sister sees herself. You’re saying that she sees herself as ugly, and you see her as beautiful. You also say that she has low self esteem, and you want her to see how great she is. I’m wondering if maybe you’re conflating issues that seem the same to you, but which seem very different to your sister.
Sometimes people who have tremendous respect for themselves as people feel ugly. Sometimes amazing, wonderful people really *are* very unattractive by conventional standards. And for some people, it’s really powerful to come to the conclusion that don’t need to be beautiful to be ok. I don’t know how the world looks to your sister, and I don’t know what she’s struggling with. But it may well be that trying to see herself as beautiful is not what’s right for your sister at this point. And really, she’s the only one who know that; you can’t tell from the outside; you can only guess.
Your sister may be struggling tremendously with her self esteem, she may be struggling to feel worthy. But it’s her struggle - you can’t do it for her, and you can’t make her do it faster. This is something she has to figure out for herself.
It’s hard to see someone you love struggle, particularly when you think you know what would solve things, if only they would listen to you. Taking over really doesn’t help though, particularly when someone’s main problem is that they don’t respect themself enough. You can’t give someone self-respect by trying to force them to override their own judgment in favor of yours, as tempting as it might seem.
You can’t take over or direct your sister’s path to self-acceptance and self-respect, but you can support her in powerful ways. The best thing you can do for your sister is to respect the way she feels about herself now and stop trying change her. 
You can’t make your sister think that she’s great. You can’t make her think that she’s beautiful.
What you can do is acknowledge that she feels ugly, and show her respect and love as she feels this way. What you can do is be with her anyway, and show her that feeling ugly will not make you abandon her. 
Don’t get angry or upset at her for not feeling good about herself. That is counterproductive. If you express exasperation with her over this, it ends up sounding like "I want you to like yourself NOW NOW NOW you’re beautiful", which on the receiving end can be heard as “I hate you for not loving yourself more”. That is the opposite of the message you’re trying to send.
I think the best thing you can do for your sister right now is accept that, right now, she doesn’t feel great about herself. Your sister’s poor self image is not an inditement of you. It’s not your job to fix it - but you can be there for her while she figures things out, on her own timeline.
You can’t try to change your sister’s self-image without hurting her. What you can do is show her the love and respect that you wish she’d show herself.