I was told that even if a smoker does not smoke around a child, changes their clothes after a smoke and washes themselves that it still puts a child at a higher risk of developing asthma. BUT I am pretty sure that would probably involve repeated exposure.

I think you should just be firm with your MIL and say that it is your choice that you do not want your DD exposed to any of the toxins. If she questions it remind her that she is YOUR DD and it is YOUR choice.

GL!
Janie xxx