Like a governess, a lady's companion was not regarded as a servant, but neither was she really treated as an equal; however her position in the household of her employer was notably less awkward and solitary than that of a governess. Only women from a class background similar to or only a little below that of their employer would be considered for the position.
The description highlights the ambiguous nature of a lady's companion's role within a household. While not a servant, she wasn't truly an equal either. Her position was less isolated and more comfortable compared to that of a governess, but only women from similar social classes were considered for this role.