Classical Academic Press has several levels each of Spanish and French for younger learners. Spanish for Children and French for Children.
Memoria Press has two levels of First Start French, listed as grades 5-8.
Breaking the Barrier has Spanish and French.
https://tobreak.com
Little to no experience with any of those.
I can recommend the following for a good introduction for beginning middle school and up students: the Getting Started with Spanish or Getting Started With Latin, by William Linney.
There is also one for French.