What literary device is this?

Question

She tried to pretend she was fire.

Answer 1

It is a metaphor.

She is comparing herself to fire without using like or as, which would then make it a simile.

I would personally not consider this as fact as the previous respondent - she is not really fire, thus it cannot be a fact.

I do not understand how it could be irony. Here is the definition of irony:

http://dictionary.reference.com/browse/irony

1. the use of words to convey a meaning that is the opposite of its literal meaning: the irony of her reply, “How nice!” when I said I had to work all weekend.
2. Literature.
a. a technique of indicating, as through character or plot development, an intention or attitude opposite to that which is actually or ostensibly stated.

It could be hyperbole- perhaps since that means exaggeration. But it would still be a metaphor .
http://dictionary.reference.com/browse/hyperbole

I am an English teacher. The only answer I would accept is a metaphor.
http://dictionary.reference.com/search?r=2&q=metaphor

1. a figure of speech in which a term or phrase is applied to something to which it is not literally applicable in order to suggest a resemblance, as in “A mighty fortress is our God.” Compare mixed metaphor, simile (def. 1).
2. something used, or regarded as being used, to represent something else; emblem; symbol.

Answer 2

It's a statement of fact. Depending on context, it could be irony, symbolism, or hyperbole.

Answer 3

Nebulous bombastic contrivance.