The girl with the keys? (6)
I believe the answer is:
joanna
This clue might be a double definition.
'the girl' is the first definition.
'with the keys?' is the second definition.
The definition suggests a singular noun which matches the answer.
Can you help me to learn more?
(Other definitions for joanna that I've seen before include "east end piano" , "One's played" , "Piano (rhyming slang)" , "Girl's name, piano" .)