Overall, how much a tutor charges depends on their own level of education, mastery of the subject, and experience. Are you a native speaker of Frech? Have you passed the AP French Language and Culture exam with a 5? Have you just taken French III? What would you do? Just help the kid with their homework? Do you have any teaching methods or tools? My thinking is that you would charge whatever a babysitter in your area would charge per hour unless you have some extraordinary background. The other issue is that you'd need to tell your prospective clients that you wouldn't be available to help them during the last month of school and during finals. That might be fine for them or a deal breaker. It is also quite possible that some parents would not want a pregnant teenager around their impressionable teenagers.