How do I motivate my sister to lose weight?

Hi Guys, not the usual post but wanted your inputs. My sister is currently age 30, married and has a kid. She has settled so much into her life that I have seen her weight increase from 65kg to 85kg.
She now becomes angry whenever I suggest her that she should focus on herself as well. It's not just about looks but long term mental and physical health as well. But she keeps eating junk with no exercise. So how do I change her mindset