Sarah,
I appreciate that some feel called to work to get prayer and Christian teaching back in the schools, just as some are called to be light and salt in a dark place by teaching in public schools. But the public school system is a government school system unsympathetic to God's agenda in any area and broken, in my opinion, beyond repair.
Best case scenario is to work to provide vibrant, healthy alternatives for children's education. Homeschooling is a wonderful adventure that I heartily recommend. A good Christian school (and there are bad ones and good ones out there)is a wonderful resource for parents and the whole community.
You bring up an excellent point: having God's word memorized is essential--it will pop into your head when you need it, helping you to make wise choices. Pray for your grandchildren, and always let Christ's love flow through you to them. Even if you are not allowed to name the Name of Jesus, they will eventually ask you about Him if they experience His love through you.
Thanks for reading!