Summer english classes for niece from mexico??

we would like to invite my husband's 16 year old niece to spend 4-6 weeks with us in the summer. We are wondering where she could take english classes for a few hours a day? i am guessing she can not go to public school summer school programs but havent really looked into it yet. any leads would be greatly appreciated. We live in San Leandro but could travel to parts of Oakland or Alameda.