"As safe as riding a motorcycle" is the usual one ...
... except that most motorcyclists are killed by other people outside their control, whilst many pilots kill themselves ...
... so you explain to her that you load the dice in your favour by
(1) obsessively reading the accident reports
(2) making sure you personally don't do any of the dafter things mentioned in them.
Thus, whilst the overall average death rate for pilots remains similar to that for motorcyclists, your personal chances are rather better than that. Press this home by cancelling the occasional trip because the weather is iffy or because you're feeling a bit tired or something.