I personally feel that "can" is somehow more inviting, more "sure-no-worries-get-in"-ish, while "could" suggests to me that the speaker is sort of resigned, as if they felt the girl will get in irrespective of their opinion. I would still favor "can", though.
I personally feel that "can" is somehow more inviting, more "sure-no-worries-get-in"-ish, while "could" suggests to me that the speaker is sort of resigned, as if they felt the girl will get in irrespective of their opinion. I would still favor "can", though.