Based on his own timeline and his life along with her own tragic end, I would say that Malcolm's days in New York before he fled to Boston would have to have been the last time he was able to see Billie Holiday.  Being introduced to her by his brother and in his experience of the New York and Harlem nightlife, this was the time when he spent time with her the most.  When he leaves for Boston, it is unlikely that she went with him.  His time in Boston was interrupted by his prison sentence.  After Malcolm serves his time in prison, he is released in 1952, at which time he completely surrenders himself into his work at the Nation of Islam.  While Holiday was still singing at this time, it is unlikely that Malcolm would have spent time with her or even seen her as her state of being represented the antithesis of Malcolm's teachings.  Given where she was as the time in her own life, it is unlikely that she would have seen or spent time with Malcolm, as well. With her death in the late 1950s, Malcolm was probably too consumed with his work with the Nation of Islam to notice.  I think that this would make his time as a young person in New York City as the last time he would have seen her.