Hannah Vogel is a newspaper reporter.
She is also a part-time spy for British Intelligence though when we first meet her that has not yet started but her crime-reporting journalist duties have been going on for a couple of years. Not that anyone reading the paper would know her despite the popularity of her work for in the early 1930s in soon-to-be Nazi Germany, female reporters, few as they were, did domestic pieces and possibly gossip articles, not murders and muggings and rapes and other mayhem. For those reports she has used the male pseudonym of Peter Weill and it was under that name that she is known for balanced, straight-forward detailing of who done what to whom.
One of Vogel's many talents, in addition to her ability to listen and really hear, is her drawing which in the courtroom where cameras were not permitted, was exceptionally important to be able to show as well as write about the cases she covered. This, coupled with a very good eye for detail, would prove valuable when she starts her secondary job as an operative. Throw in now firmly established credentials as a reporter and an attractive smile and figure and she got into places many other could not.
I could not find a particular age for Vogel but she talked of having lost a fiancé, Walter, in "the war" which had to be WWI. Even if she had become engaged near the end of the war and was in her late teens as was not uncommon then, that would have her born around the turn of the century and thus 30+ years old when the first of the recorded adventures take place. This is important for understanding the high level of maturity she consistently shows frequently.
Playing a very major role in her life from shortly after the start of the first book through the rest of her stories will be Anton, a young boy and her "son". The tale behind that relationship is worth the price of admission all by itself.