She wasn't indoctrinating the children; she was attempting to undo the indoctrination they had already been subjected to.
But, I would imagine the good bus driver was talking specifically about fetal stem cell research.
Now, when you explain Fetal Stem Cells you would have to mention things like sex and conception.
How, Lovely, A School Bus Driver Conducting A Sex Education Seminar on the way home from class.
Would it be okay if you left it up to my wife and I to teach our kids about sex?