Thanks, Nate (@Naters-Calderone) and Lynn (@Lynn-Larson)!
I am using quite cheap pens. In this I used two kinds: a Stabilo Greenpoint with 0.8 mm tip and a Schneider Topliner 967 with 0.4 mm tip. I am not sure how known they are outside Germany.
How nice to ask for a name!? :-) I like if the name of a character is somehow contrary to his/her personality to cause a kind of surprize for the reader, when the characters behavior does not really match the expectations. I am not an expert and it would be interesting to hear what Lee (@Lee-White) is saying about this.
For German ears this girl looks like a Gertie, which sounds very diffident and well-behaved. If you prefer to go for a more cheeky name then I would propose a boyish name, like Kim. I don't know why but I find also a french name pretty good for her like Gabrielle. These are my proposals :-). What do you think?