Most Helpful Guy
1. Caloric deficit to lose weight and get rid of facial fat clouding facial features. I'm of the opinion that most people will be good-looking as long as they have low body fat % and haven't walked into a brick wall recently. In your case, you're shorter so fat fills you up more easily, so you need to have less fat than your sis.
2. Since you're losing fat, you're prob also losing some curves. Google exercises to increase muscle mass in the right areas of your body to replace the fat (more muscle = easier fat loss due to how calorically [if that's the right word] taxing it is to maintain). You said she's thin, right? Do squats & stuff to get big butt and thicker thighs to gain a more curvy appearance. Curvy > thin; it's what guys are drawn to (source: science). There's probably more exercises to increase hip width and stuff. I haven't really looked into it because I don't want to have wide hips, but I've skimmed over some stuff about that.
At some point my jawline had some pretty nice definition, then I gained a few pounds and lost that definition. I've lost most of that weight now and nearly regained that definition. So, yeah. Fat loss is a big deal for facial looks. Gonna go even lower than I was before (body fat % wise). I'll be cutting glass with my jawline soon.
Just so you know, if you have a good body most people won't even care how facially attractive you are as long as you don't look like a zombie.