Shouldn't that be "she is taller than I"?
She is taller than me.
She is taller than I am.
Comparative adjectives: using than
We use than when we mention the second person or thing in the comparison. If the second person mentioned takes the form of a personal pronoun, we normally use the object form of the pronoun (me, you, him, her, us, them):
Could you carry this? You’re stronger than me.
Not: You’re stronger than I.
Why did you choose Robert? Marie is more experienced than him.
In more formal situations, instead of than + object pronoun, we can use than + subject pronoun + be:
You managed to answer the ten questions correctly? Well, you’re definitely cleverer than I am!
I preferred Henrietta to Dennis. She was always more sociable than he was.
The comparative form is used for comparing two people or things:
He is taller than me.