I met her first at a White House event around St.Patrick's Day in the mid 1990s.
She was a gawky, teenager then, growing pains very evident, but what impressed was her nice easy manner and her ability to make you feel at ease.
The Dad's political magic had rubbed off somewhere.
I remember her mother Hillary saying that Jackie Kennedy had been a great inspiration and source of advice to her on how to bring up Chelsea.
Indeed, when you compare those two poised and successful ladies, Caroline Kennedy and Chelsea Clinton, you can see the similarities.
Chelsea and I next met during one of her father's triumphant trips to Ireland.
I knew she had done her thesis at Stanford on the Irish peace process and was delighted to discuss it with her.
She impressed me with her grasp of the topic.
We agreed it had been one of her father's greatest moments in power when the IRA ceasefire happened after he had taken a huge risk on the Gerry Adams visa.
The next time we met was when her mother was running for senate in New York and was attending our inaugural Irish Voice Top 50 Women.
Before going on we chatted backstage.
It was clear Chelsea was suffering from a haymaker of a cold.
She was in bad shape and her mother was quite worried about her, wanting to cancel the rest of her schedule.
Chelsea insisted she go on however, a steely determination evident that her mother not lose a single opportunity to get her message across on why she was running for senate.
The dynamic between mother and daughter was evident to me that night.
They are quite simply, best friends, who have shared trauma, heartache and thrilling triumph together.
Close staffers told me that Hillary was simply much better on the stump, in much better form, when Chelsea was around. A daughter can share no greater love than that.
The most recent time I met them was during the New Hampshire primary when Hillary was down and out but fighting back like a tigress.
Chelsea, who had seemed nervous and tentative speaking at public events in Iowa suddenly hit her stride too on college campuses and they pulled off a famous victory.
My sense of Chelsea is never to rule out a run at public office for her.
She has a combination of the parent's dynamic populism which could wow crowds in an instant if she ever decided to run.
That is for long in the future.
This week she marries.
If she is half the wife that she is the daughter to Hillary and Bill to her new husband he will be a lucky man indeed