Jane is treated as most 19th century governesses are treated. She is a servant, but she maintains a higher role in the household than other domestic servants. This is because she is educated and she has the responsibility of teaching a young lady academic and social skills. Thus, she is allowed to attend events such as dinners and engage in conversations that the other servants would not even consider being involved in (or be allowed to).
Of course, in Jane's situation, she becomes Rochester's trusted confidante and love interest; so she is treated better than most governesses would have been in her time period. The link below contains helpful information about governesses during the 19th century.