I look at it this way:
Finland, the country with the one of the best academic standings in the world, does not even remotely start learning until age 7.
Waldorf education, does not start learning until age 7.
100-200 years ago, most children that attended school only received 4-6 years of formal education, and their vocabulary, grammar and writing skills far surpass our own today.
Charlotte Mason herself, does not recommend starting academics until age 6 (so not even this year!)
If you want to look back at the history of education starting at the Medieval age, clear back to the Greek and Roman beginnings of education, it was approached much differently in the classical world: a child learned the art of grammar, logic and rhetoric first, and then the work in the sciences (including math) did not start until they were much older, into their teens.
Over the thousands of years of history of education, it has always traditionally started later and/or lasted less time – and I would say, produced better results. Many of our greatest academics, thinkers, inventors and innovators have come from an era of delayed academics and/or less academics: Copernicus, Galileo, Einstein, Shakespeare, Isaac Newton, Abe Lincoln, Thomas Jefferson, Johannes Kepler and this is just a tiny fraction of them.
While, I would tell you it really doesn’t matter what people think or say, because it’s your job to do what you feel in your heart is best for your child, you could always tell them to look at history, other countries, and to learn about other educational models.
So, for starters, I would say – don’t even feel you need to do MFW this year! Feel free to give her another year of just play and cuddling in your lap reading stories. Put MFW off until next year. However, if you want to continue it, then by all means, feel free to spread it out over two years. Perhaps just do it 2-3 days a week.
Really, the most important things we can teach a child before the ages of 6 are to enjoy reading (a far different skill than learning how to read), to observe (focus on Nature Study, teach them to pay attention and observe the world around them), and of course to be obedient and love the Lord. If we can teach a young child those things in the early years, then we have laid an excellent future for when academics start.