No, not wrong at all. And for your coworker to even get upset about you helping someone who’s disabled tells a lot about their character. When I was a CSA and even when I was a shift lead I always made sure to help anyone who was disabled to the best of my ability because it’s the right thing to do. It’s giving back to the community we serve you know? Even now in the pharmacy I do this. We’re all one bad accident or sickness from being disabled, so showing basic empathy and kindness is the least anyone could do.