TBH I am a little shocked by some of the responses saying that it is unhealthy for dcs to be a Mums whole world.
Personally, I would aim to strike a balance between kids, DH, friends, other family and social interests/work. However, I don't think its unhealthy if someone chooses to make kids the centre of their world, its all about how they choose to live their life and if they are happy with their choices.
I would say this statement would completely describe my mother, only she might have said "my family is my whole life" as Dad was/is central to her world as well (well actually I could never imagine her saying it but she would think it). She was a SAHM for all our childhood and most of her adult life (she had me at 23, brother at 25 and sister at 29), I was never left with a babysitter, she lived hours away from her family, she had no real friends apart from other kids Mums (and even then she rarely socialised with them) and didn't work even when we were all at school. Despite this she was incredibly happy, all she ever wanted to be was a housewife and mother and she found it incredibly rewarding. She was active in our school, volunteering, on the PTA, then the govenors and was eventually chairman, but of course that was still revolving around us in a sense. Dad worked long hours in the city so Mum was always there for us when he could not be. That was how they both choose to bring us up. We were never smothered, we all turned into well balanced, happy successful adults. We were not "harmed" in any way by her choices. Now we have all left home she does volunteer work, has a few friends who she "lunches" with, she takes the dog for a walk but is generally content being a housewife. Personally, I couldn't do that but she is very happy living like that. She loves the time it gives her, her and my Dad often spend 3-6 months abroad every year as he is a self employed consultant so only chooses to work for part of the year.
I would not dare pass judgement on my mother for choosing to stay at home, she has always been the anchor of our family, always there for us when we needed her and just because she chose to do it in a way that is not for everyone (including myself) does not make her less of a good mother.