The OP did not ask whether or not anyone thought she should push her kids in strollers - she just asked about sizes. I don't think it matters one way or another who rides in a stroller!
How do you all know the health status of any poster's children anyway? Some people don't want to come on here, and list their children's medical issues just to get info on a stroller. Maybe some people just wants to come on here, get the information, and tell the rest of you that the medical issues of their children are none of your darn business.
It is also very telling that the ones who are judging the OP are also the ones who say they laugh at kids and say their own children's actions are controlled by peer opinion (which will not be a good thing as teenagers).
My DD6 would actually not care if other children saw her in a stroller. If she wanted to ride in the stroller and someone told her that others would think it was silly, she would shrug her shoulders. She has never been a blind follower of anyone. And she is also the first one to stand up for another child she thinks is being laughed at or bullied.
Luckily, when we were there a few weeks ago, there was not one comment made about her being in a stroller. No one gave us odd looks. No one said a word. And for all you who think you know everything, she has arthritis and no, you wouldn't know it from looking at her.
So laugh at children and teach your kids to laugh at others if you want to raise mean spirited people.
But my daughter is a loving person and a leader. She isn't going to give into peer pressure or be a jerk because others are. OP, ignore the mean people and don't let strangers ruin your vacation.