"Call Girl" appears to be a complete fabrication. Gold digger? Sure. Sex worker? Hardly. None of the cartoons indicate that Lilli is a prostitute. Even the Wikipedia page says she's a secretary.
The story used to be notable because it's a bit bizarre that a popular kid's toy was a carbon copy of a highly sexual cartoon character aimed at adults.
If a popular kid's toy were merely a carbon copy of an existing German cartoon character, alone, it would not really be notable at all.
I appreciate the sensitivity around putting labels on the character, especially on a professional setting such as HN, but it's a detail important to the story.
This one is not that different from Betty Boop. Many movies and cartoons had both childish and adult themes intermixed before the Hayes moral code kicked in.