solution: "she walks in beauty" incorporates simile. If you read the complete line, it is "she walks in beauty, like the night..."; as movement of woman is compared to the movement of night sky using the word 'like', it is simile.
"a heart whose love is innocent" incorporates personification as it attributes human characteristic of innocence to woman's heart (non-human) to say that her inner qualities are as good as her appearance.
