I keep reading that you can't have prayer in school anymore
You can pray to yourself all you want to. You can carry your bible to school and study it in study hall.
Heres what you can't do. You can no longer have organized prayer. The diverse religions make the Lords prayer a religion specific prayer but if you want to say the lords prayer you can do it on your own.
If you want your children to recite the lords prayer in an organized manner you will have to take them out of public school and put them in some Christian school.
There are a number of problems when a public tax supported school has organized prayer. People of different religions don't want to recite the lords prayer. The children of less than pious parents such as but not limited to atheists don't want to recite the lords prayer.
Jehovahs Witnesses will walk out of the room if a religion other than their own recites a prayer of any kind. Organized prayer creats unpleasant scenes like this and it should be banned from public schools.