"Your daughter won't break it; it's plastic."

Translation: Ta fille ne la cassera pas, elle est en plastique.

[HelenSmith409579]

Just wondering if there's a clue whether the it is masculine or feminine. Could it be either as long as the 2 'its' agree.

[Seattle_Scott]

I would think you could also say "c'est en plastique", because we don't know what "it" is.

[JohnHowe]

I just tried the answer using 'le' and 'il' and it was accepted.

[howcheng]

Theoretically, could the "elle" refer to the daughter?

[Oemerich]

I think 'no', not without changing the "elle". I dimly remember it's possible not but you'd have to use something like "elle-là" or something like it.
Per standard, the pronoun "elle" refers to the closest (= most recently) mentioned object, thus in this case the other "it". ;)