Kay...so is it an actual person/being/entity?
If so, is it someone she knows personally?
If not, is it a figment of her imagination (i.e. imaginary friend)?
Is it HER (i.e. alternate reality, from the future, etc.???)
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)