I had a very similar experience earlier in my recovery. A woman I know brought her 7 year old daughter to a meeting. Her daughter is a classmate and friend of my son (he is 8). My kids have never seen me drunk.
I did worry about it at the time but nothing came of it. It has never been mentioned by my son.
I think kids at that age take things on faith. When I go to AA meetings, I just tell them I'm going to see my friends. They are too young to comprehend alcoholism or addiction. What they do understand is getting help & helping other people. I think at the right time, I will tell my kids that I used to drink, it was a problem, I needed help to quit, and now I help others do the same.
In the past 18 months, I have had my anonymity broken maybe 6 times (people see me going into meetings, I run into someone at an open meeting). It's uncomfortable but again nothing comes from it.
I'm willing to bet that in a short time, this will be a non-issue for you.