Yeah, I asked her why she said that, and she said in school what they had been talking about or amongst her friends and what's going on. She seemed to be under the impression that as a Christian, she could not believe that evolution was a science that, you know, was true.
A Christian can't believe in evolution. 
The statement does not say definitively whether a true Christian can believe in evolution. It simply says that this girl was under the impression that a Christian couldn't. But the passage does not say whether it is true or not.... 
( z1 possible :polarity - :ARG1 ( z2 believe :ARG0 ( z3 person :mod ( z4 religious-group :name ( z5 name :op "Christian" ) ) ) :ARG1 ( z6 evolve ) ) )