comparing pregnant woman

So this is the second time my mother made a comment to me that I'm bigger than my sister in law at X amount of weeks. She made a comment the other day (I just flew home so she hasn't seen me since 16 weeks, I'm 28 now) she compared me to my pre pregnancy 135lb sister in law when I was 155lb pre pregnancy. I said everyone carries differently she's like exactly I'm like so why are you comparing my pregnancy to others