not on Underground alone - Kingston (assuming upon Thames) is SW of London and you'd need to get a train from Waterloo(?) - search on transport for london's website they can give you a variety of options
I'm in central London with work later this week and have a friend who lives in Kingston so was just weighing up the feasibility of visiting her while I was down there (my London geography knowledge is crappola)
It's feasible. But you should definitely check on return train times - unless you're staying with her overnight. I live on that line and in my experience, trains coming back to London tend to stop relatively early.