French-language schools are having a lot of success. Based on the literacy tests, which are now standardized, the schools' performance is very good and the students at French-language schools are very often bilingual almost by necessity, given the majority anglophone situation. When they leave French schools, students are necessarily bilingual and have a good knowledge of the language. The level has vastly improved in the past 10 years or so, as the literacy test results show.
As for French second-language instruction in the English-language schools, immersion and core French are working well. French is mandatory up to grade 9 and optional thereafter. A number of students drop French after grade 9, as soon as it's no longer mandatory, because they have other interests.