Beatnik girls were pretty and had long, straight hair. That part I liked.
I think it was 1961 that my uncle took my cousin, brother, sister and me to New York City. I remember going to Macy's and eating lunch there, going to the observation deck on the Empire State Building, the Statue of Liberty, eating dinner in Chinatown (where I ordered a hot dog!). My uncle took us through Greenwich Village and we walked around checking out the beatniks. The artists had their paintings displayed along the sidewalk. I remember going into a coffee house and listening to folk music and poetry readings and smelling "burning rope" (pot) :-) and afterwards, seeing a beatnik girl, just as your described, long straight hair, pretty, wearing sunglasses at night, walking what looked like a mink (it could have been a ferret). We had bongo drums at home!
I think it's a requirement to have a set of bongos, clear evidence of subversive thinking. You can bet there's a copy of Maos' little Red Book on the shelf!