1.3 million mg of tar from smoking? Read on -?

I got this app, and its a smoking quit app, I don't smoke ( my mum does) and it asks you all these questions and it says she has consumed 1.3 mil mg of tar in her lifetime. How much is this what's it equivalent to and how much damage has this most likely done to her, I want to scare her to stop smoking before something happens to her but I also am interested in how much this affects people, 10 points best answer.