Translation:Can your girlfriend ride a motorcycle?
why can't I translate this sentence as: is your girlfriend able to drive a motorcycle?
I'm not sure that "drive" is appropriate for "motorcycle"; I've only ever heard "ride".
Neither "Is your girlfriend able to ride a motorcycle", nor "Is your girlfriend able to drive a motorcycle" - both are rejected.
"Does your girlfriend know how to drive a motorcycle?" accepted 2 Jun 2019
Bike can mean a motorcycle and should probably be accepted though I understand the confusion it could make ☺
In this sentence you’d use the imperfective form «гонять». Yes, «Твоя девушка умеет гонять на мотоцикле» is actually possible colloquially, with a specific subtext that she does it well and/or fast.
Is this something that requires know-how? Driving a motorcycle, yes, but riding on one???
In the parts of the US I've lived, it's "drive" if you mean "operate". "ride" means to sit on the back seat while someone else drives it. Same for TV shows, but then the writers live in California and New York, mostly. But then, I haven't lived all over the US.
I put "Can your girlfriend go by motorcycle?", and it was marked wrong.