Poor angel. The poem really makes you pity her. But it doesn't answer who she is - is she anyone?
Some of the rhymes with 'the angel who's bound' are a bit... mnyeh... I dunno they lack punch. It don't have to rhyme, my dear.
Also, the fact that it IS at the end of every line... it kinda... snaps it off. It's lyrical then BANG. Either make the stanzas longer or something, it's a tad harsh and choppy as it is.
Anyway it's nice, I like the theme, sad and almost haunting in a way.