How about simply saying "Nobody really knows how life on Earth began?" They can then suggest various hypotheses, but they should make clear that such things are, and probably always will be, impossible to know with certainty because there are many possible initial conditions that would have yielded, to all detectable accuracy, the same result.
But that's basically what the textbooks do say about the origin of life.
Unfortunately evilution theologists demand that children be force fed the whole religion. From the primeval soup creation myth to the Adam and Eve are children of the monkey god story. To allow the above statement to be made and questions to be asked undermines and subverts the communist and athiest goal of destroying Christianity. This isn't about science, it's all about stamping out Jesus.
We know a remarkable amount about the nature of early life on earth, considering how long ago these events were. Saying "Nobody really knows, so let's throw all the hypotheses out there" makes it sound like they're all equally likely and equally supported by evidence. Nothing could be further from the truth. There is *zero* scientific evidence for divine intervention, 'ID', creationism etc. None. Nada. Zip. Zilch.
It's frustrating, having spent so much of my life immersed in real sciences, to see so many people eager to abandon science in favor of mysticism and superstition.
Evolution is not about how life began.