I know people who were raised going to Mass every single week since infancy, they received first Communion, Confirmation, private Catholic schools etc. and yet choose to ignore a majority of Church teachings.
And then you have myself and my first cousin. We were both raised in non-religious households (although baptized Catholic as infants). I became interested in my Catholic roots when I was around 16, and have been in love ever since. Before I went to Church on my own, I hadn’t been there in over 10 years. My cousin was just confirmed two weeks ago, and also attends Church regularly. The two of us are the only ones out of our siblings that attend confessions, adorations, and Mass. He is a very intelligent young man, knows very much about the Church and history in general. He is now considering priesthood.
How did both him and I become so passionate for this, when growing up, we were not exposed to it? I still don’t know!
My point is, that no matter how Catholic, or “un-Catholic” you raise your children, in the end, they’re going to do what they want to do. It reminds me of the whole nature vs nurture idea, and that one could possibly overtake the other. In this case, you could raise the children as Catholic as you would like (nurture) but there is no guarantee that this is what they will choose to remain in.
God bless you, you sound like a very genuine, concerned and good parent. It sounds like you did a terrific job of raising them. I will pray that your children return home to the Church.