I had chicken pox when I was in second grade--a very mild case, sitting out in the yard on a blanket with my brother playing board games for a week. It was fun.
When I was nineteen, I was home from college and looking for a job as a nanny. One of the kids at one of the houses where I interviewed infected me with a second case. It was the sickest I have EVER been.
Pox in my nose, down my throat, on my eyeballs. Hours of laying on the couch staring up at the ceiling because I was too sick even to watch television or sleep. Chicken pox as an adult (or near-adult, at least) was a very different thing from chicken pox as a kid. I wouldn't take the chance of causing that experience for anyone.
Apparently some of us who have had it mildly as children are not as immune as we think we are. I would not get the vaccine. However, I will keep your story in mind as I evaluate my and others' exposure.