Hi Tomato. When I was in middle school, I had a friend that loved to eat. Lol, so I fed her. She didn't have a stick thin frame, but was one of those "early bloomers" that had it ALL going on in All the right places and I was my same ole chubby self but my weight never went to my boobs just my belly and butt. So, she kinda made me jealous...... that said, we'd go to the local icecream parlor (

) and order a hot fudge sundae to split. I'd take a few bites and insist that I'd just eaten so she should finish it , if she wanted (hey, it salved my conscience by making it her choice lol) .
Of course , being raised by her grandparents , she never left food uneaten... needless to say, I think she gained about 20 lbs in a couple of summers.... I didn't get boobs till I got pregnant, but at least she gained a bit of a tummy in the interum .
Not nice, but effective
Anyway, your skinny friend sounds like she has a revved metabloism which maybe something to covet. But remember. People, especially women, that have thinner frames and have been and always be skinny also tend to get osteoporosis more often. And that, isn't something to covet. Also, maybe she has alot of "nervous energy".
She could also be putting on "airs" for you. She may be one of those people that eats in front of people to show that she doesn't starve herself, but then goes days without so much as a nibble to make up for it when noone is looking. You aren't with her 24/7 so you don't know what goes on behind closed doors.
You just worry about you and your health and your journey. We will all make it through this and come out healthier and hopefully a bit smaller in the process.
Kim SW 243 CW 203.8 GW 135
All the Dreamers are Dieting
It takes a lot of courage to show your dreams to someone else.--Erma Bombeck