The former PM's wife criticised women who "put all their effort into their children" instead of working. And she said mothers who go out to work are setting a better example for their children.
The QC and mother-of-four made her controversial comments at a gathering of Fortune magazine's Most Powerful Women at posh London hotel, Claridges.
She said she was worried that today's young women were turning their backs on the feminism of their mothers' generation, with some women now regarding motherhood as an acceptable alternative to a career.
Instead, women should strive for both, she said.
"Every woman needs to be self-sufficient and in that way you really don't have a choice - for your own satisfaction; you hear these yummy mummies talk about being the best possible mother and they put all their effort into their children," she said.
I also want to be the best possible mother, but I know that my job as a mother includes bringing my children up so actually they can live without me.
The wife of former Prime Minister Tony Blair also accused some young women of seeking to "marry a rich husband and retire" instead of working.
"One of the things that worries me now is you see young women who say: 'I look at the sacrifices that women have made and I think why do I need to bother, why can't I just marry a rich husband and retire?' and you think how can they even imagine that is the way to fulfil yourself, how dangerous it is," she said.
Mrs Blair said her view was informed by her own experience of her father abandoning her mother when she was a child.
But she insisted that all women should make sure they can provide for themselves: "Even good men could have an accident or die and you're left holding the baby."
Despite Mrs Blair's worries about non-working mothers, official statistics show that the proportion of mothers who work has actually risen in recent years.
According to the Office for National Statistics, 66 per cent of mothers are now in some form of paid work. In 1996, the figure was 61 per cent. The number of working mothers is now around 5.3 million, up from 4.5 million in 1996.
What do you think? Is it high time we stopped splitting ourselves into two opposing camps - working and SAHMs? Aren't we all just doing the best for our families and ourselves?
And don't our working lives change and adapt - full-time, part-time, stay-at-home, returning to work, flexi-time, working from home?