She is a character from the movie The Great Mouse Detective that initially released in 1986. It was later re-released after the success of other Disney movies like The Little Mermaid and Aladdin. I believe it is not that widely known since it didn’t have any exceptionally memorable support charters like Sebastian and Iago which were in the other movies. But well, that’s just my view.
It was one of those days when I just wasn’t able to get myself to sketch. It was late in the night and as soon as I saw this, I had to make it. So, I sat to make it. It was complete in 20 mins and I slept happily knowing I didn’t waste my day.