When elizabeth barrett browning writes in sonnet xli that "'my future will not copy fair my past,'" she means that

When Elizabeth Barrett Browning writes in Sonnet XLII that "My future will not copy fair my past" she means that her future will not be the same as her past.

Explanation:

Elizabeth Barrett Browning was a poet during the Victorian Era. In her "Sonnet XLII" she writers that "my future will not copy fair my past" to indicate a phrase she wrote when she was young, stating that her future was not going to be the same as her past. She remembers that memory of her writing that phrase when she was older and believed she was about to die, when actually she was about to be saved by love.

The poet means that "her future will not be the same as her past because she will be responsible for writing it differently".

Explanation:

"My future will not copy fair my past" is the first line of Sonnet XLI and expresses the main idea the speaker is going to develop throughout the rest of the lines. The speaker expresses that first line as something she/he wrote once, and this is the reason she means it is going to be different in the future because she/he will be responsible for writing differently from now on, which is also expressed through the rest of the sonnet.