Hiring a tutor to maintain 2nd language

For the 2024-25 school year (and possibly beyond), we are thinking of hiring our son's former Spanish teacher to tutor him so that he keeps the language going. She is open to the idea but we haven't talked about any details yet, and I want to be sure we do this right. For others who have hired a language tutor recently: (1) how much do you pay them?; (2) how often do you think they need to work with your child in order to make meaningful progress in the language?; (3) anything else we should be mindful of? Our child is almost 11 and has attended a Spanish immersion school most of his life, but will be switching to a non-immersion school next year. His teacher will still be teaching next year so I assume we'll need to plan on some weekend-only tutoring. 

This is all new territory for us, so we appreciate any advice. Thanks!