Well, I suppose that's the way it is in the 19th century. But I also know that it would be a totally different story if Charlotte had been hired as a "lady's companion".
Especially in England, where Charlotte is from, a lady's companion is not at all thought of as a servant, although at times she might be under-appreciated by the family that hired her. But, the reality is that her background and social class would be similar to her employers.
Charlotte's situation is quite different. She worked on her family's farm in England, and then in a factory - she has no class status of her own.
Because Charlotte is unmarried (and is also missing two fingers because of the factory accident), her options for employment are quite limited. It seems to me that being your lady's companion would work out well as she is a few years older than you, which is a requirement; but of course this is not my decision.
What would her role in the house be?
To take care of all your needs and wants, of course!
Thinking about what I just said?
It does seem like the perfect solution to get Charlotte out of her funk, right? Just make sure you let the family you live with know that it is Charlotte you would like as your lady's companion. If they hire someone else for the job, even she would end up bossing Charlotte around, as a maid's position is considered much lower than a lady's companion.