Encouragement for high school level courses
You don't have to "abandon ship" and give up on home-schooling as your children approach high school age! Many parents think they are incapable of teaching upper level courses, and have to turn their children over to "qualified professionals” at that point. The most important thing that you need to know is that EVERYBODY will eventually feel overwhelmed and under-qualified to teach something. In our home-school, I was pretty good with math, but once my children got past Geometry, my ability to help them started to ebb. When they got into Pre-Calculus and Calculus, I was totally lost, and didn’t even know what the symbols meant anymore!
As your children approach high school age, it’s helpful to realize that you are no longer teaching children, but young adults. It’s also important to remember that your goal is for them to start learning to teach themselves - a skill that all adults will need at some point. This is why you don’t have to understand every subject that your child learns! Your job is just to make sure that your child learns what they need to know. There were plenty of things that my children learned that I didn’t learn or know. I followed along with the first six months of French, but they took French for 3 years. I didn’t know any Latin, but I did study with them for 2 years (and then I gave it up in the 3rd year)! Anything that involved physics was way over my head!
Whenever I purchased home-school high school curriculum, I looked for a video tutorial if possible. I gave my children the textbook and access to the answer key, and they eventually learned to teach themselves and figure out how to work through it. We used Saxon for math and Apologia for science, and were able to get any support that we needed online. Of course, the ability to teach themselves did not develop overnight - it took training and encouragement, falling down and trying again. But eventually, our sons were prepared for the kind of self-teaching that was required once they got to college. There were able to succeed partly because they knew how to learn.
Don’t be afraid that you will fail your children in high school because you don’t know everything about every subject. Don’t feel you have to abandon ship, give up on home-schooling, and send them off to someone else’s school. And don’t miss this important opportunity that high school brings to continue teaching your children—teaching them how to be ready for adult life, how to learn, and how to succeed!