Modesty Blaise's age

I just read a retrospective magazine article about Modesty Blaise, which stated that she withdrew from her life of crime at an age of 25-ish. I’ve always thought of her as doing that in her early forties or late thirties at the earliest, and in the episodes looking back at her time running the Network, she definitely doesn’t look 25 to my eye. She was already a serious milf. More to the point, if she is in fact 25-30, this takes away a lot of the character’s interest, in my opinion.

Some online attempts at Modesty Blaise chronologies agree with the magazine article. But, it just doesn’t jive with the character. She says that she feels “old and tired” and “old and sinful”. She’s got this whole “looking back at a long life of crime” thing going. Have I been misinterpreting Modesty Blaise from the beginning?

Modesty broke up The Network and retired from crime at age 26. It seems unlikely that she would be so jaded and experienced at that age. But this is Modesty Blaise we’re talking about here.
Useful guide to many aspects of Modesty Blaise