In the beginning of eclipse (movie), why does Bella say ' But if I had to preish twice ' ?

The Robert Frost poem goes

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I now enought of hate
To say that for destruction ice
Is also great
And would suffice.


But when Bella mga panipi the poem in the meadow, she says

...
But if I had to perish twice
...

Why does she say ' I ' instead of ' it ' ?
Is it a mistake they didn't recognize or is it on purpose?