I know when I was just becoming a horny teenager some much older Sisters I overheard were discussing this very point. I know you shouldn't eavesdrop, but I was facinated by the subject (natch) and by where the conversation went.
They did not discuss the Bros much, apart from saying some would sure have to lose weight, but when they got on to the other sisters wow ! it was all whose breasts were larger and more impressive, who had the best legs, with comments about the young sisters like "Yeah, but her legs are bigger at the top than mine".
I had to skulk away ..............
p.s I remember one Sis gave as an idea that "Jehovah will give us all perfect bodies, we will all be beautiful". Yeah, that WOULD be a miracle,