Am I allowed to swap my own battery?

Let me start off by saying that I really appreciate the employees helping out whether they are swapping a battery or putting some new lightbulbs in. I asked them to test my battery and we came to a conclusion that it was bad. Luckily, it was under warranty. The girl insisted that she removed and replaced my battery for me. She couldn’t be taller than 5’5 and lifting a 30 pound battery onto lifted truck doesn’t seem very practical however she insisted that she swap for me so I let her. So now I’m just a dude awkwardly watching a girl struggle. I thanked her and gave her a $10 tip. A couple of guys inside didn’t bother to help her either which I thought was interesting. Either way I really appreciate it your help, but I didn’t mind doing it myself to save someone from struggling.