My Boyfriend's Co-worker Keeps Texting Him

So this started about two weeks ago. It was Saturday around 1am she messaged him saying "You used to be a nurse right?" He goes, yes. She sends him a picture of her daughter's arms and legs that have rashes. She goes "We don't have insurance. Should I risk the bill and take her to the hospital" " He goes, looks like eczema. I would take her to an urgent care" she goes into how she really can't afford the bill rn since she's a single mom. He gave her advice on a lotion to get since he also has eczema. Ever since then every little thing wrong with her children she'll message him at random hours asking what it might be and if she should take them to the hospital. It really bugged me but when I brought it up to him he said " It happens all the time when you're in the medical field. People always come to you with your questions. Nothing to worry about". I'm trying not to be worried. After all she's just asking medical questions about her kids. IDK... Just rubs me the wrong way.