People can be so cruel about other people issues

I understand my coworker has health issues but when you put me in a area with toddlers and I’m constantly bending and twisting and trying to keep the kids in area it’s hard on a pregnant person that can’t do a lot of lifting I’m not in my 20’s I’m not in my early 30’s I’m almost 40 and it’s hard on me especially when I don’t have a Toddler at home stop putting me back in the infant and toddler area of the center I can only be on my feet for 15mins out of a hour! The last couple of days I been in so much pain because I am in a high moving area with kids under the age of 3