Find out her diet and regimen. I had a friend who was on a very strict diet while she was pregnant because she had a high-risk pregnancy. During the pregnancy, she was somehow thinner than I’d ever seen her (funnily enough, she has actually gained a lot more weight after having the kid, now that she’s no longer bound by the dietary restrictions). Could be something your sister is lucky with genetically even though you’re twins—or more likely it’s a lifestyle difference. Talk to her, find out, and try little changes in your diet and exercise. Or even big changes! Try not to be bitter about your differences, and you’ll feel even better if you work hard and reach your weight goals - you’ll look good and be physically fit/healthy. Win/win!

Pics or it's fake. Pics of her, that is. You go ahead and hold on to the ones of you. TIA

I lost weight when I was pregnant, after birth I was the thinnest I had been in years. 6 months later and weigh as much as I did the night before birth 😏 For all we know the weight loss might not last but it is probably connected to diet or lifestyle, possibly breastfeeding as well (some gain and some loss weight from it)

Well people have to have some way to tell you apart…

I feel you, OP. Though not twins, my sister never even wore maternity clothes, and I'm still in maternity clothes 18 mos later with an extra 30lbs. It's tough to watch other people live your dreams.

Stop comparing yourself to other people! I guarantee that your child could not care less about your stretch marks. And only shallow men will complain about their wives/girlfriends’ bodies looking different after they’ve given birth. Repeat after me: I am beautiful and my body is amazing!!