This book feels dated, but perhaps I shouldn't be surprised by that. Here she's looking at her like from the 1930s to the 1970s (when she's about to win the election). There isn't too much discussion of the 1930s though, because she was very young for a lot of that period. She attended university in the early 1940s.
In a way this book is interesting. I remember Thatcher as Prime Minister, so it was interesting to learn about her early life. It is her youth that shaped her, and given that she shaped the country in many ways, I think that it was useful to understand her background.
This having been said, I would say that there are a couple of major flaws with the book. First, when describing her youth, she, like many autobiographers I think, has a tendency to use "rose tinted spectacles." So far as I can tell, all the men are intelligent, women strong and children "above average" in Grantham, and I have real difficulty believing that.
Secondly a good chunk of the end of the book looks at her vision for the future. Given that that vision was written in 1995, it does feel a little dated now. Maybe it's accurate, maybe it isn't, but when she talks about GATT and the beneficial impact of globalisation, you have to look back at the last 4 or 5 years and think really?