Narrator
The narrator, presumably the voice of Lowell herself, is present in all her poems. In some of them the narrator addresses a more general audience, while in others she speaks to a specific person such as a love interest or a friend.
The Lady
The subject of the poem "A Lady," the lady is featured in an old portrait that the narrator likes to look at. Though the lady and her portrait are old and fading, she still fascinates the narrator.
"My Dear"
The addressee of the poem "A Little Song," this person is the love interest of the narrator. When they are away from the narrator, they are missed and the narrator wants time to speed up so she can see her dear again.
Audience
The audience is the both the "you" and the unspoken listener that Lowell's narrator addresses. As a character, it is able to be interpreted as either the reader or a specific person the narrator is addressing who they know more intimately.