Sick and Hungry

Which author are we talking about?

Also, there is no such thing as a design that is 100% original.

Everytime you make something, there can be 10 people that will be like "Hey that reminds me of the style/work of...". That's because everybody get their inspiration from somebody. It's kinda sad, but true. When you learn how to draw, most of the time you follow the technique of somebody else, or try to recreate the same style. As a result, it will look alike. It's up to you to mix different styles in order to find your own style.

As for "stealing"... unless your friends used the exact same design of somebody else's work (for example, a character with almost the exact same hair, clothes, facial features, etc. than somebody else's character), there is no steal. Just two drawings that use the same style. 

But if she did, however, then yeah. It was a steal. Using somebody else's work, and claim it as their own, that is stealing. Recreate an identical character that originally belongs to somebody else, and claim it as your own, or without asking for permission first, that is stealing.

But if she never did anything like that, then she did not steal.