While gender roles have evolved and provide more leeway in this day and age, they remain the same except are no longer gender-specific. Meaning, in a gay relationship, one can be the "domestic goddess" and another the breadwinner. That's not always the case; my parents, for example, both work and then bitch about the housework at a later time, and I'm the only one who can do the laundry correctly. Anyway, your mother knows nothing to insult your career choice (I have the utmost respect for teachers), and you are not lowering yourself by doing what has to be done either way and not making a drama out of it.