There are a numbner of Possible anagrams in Rachel Blake's name, such as:
Bella Hacker (A Hacker Bell)
A Lab Heckler
A Baker Hell
A Chalk Rebel
Back Are Hell
Back All Here
Relable Hack (or Relabel Hack [or Label Hacker])
Beak Call Her (Beak being a person's name, perhaps?)
Rachel Blake could be the partner of Tom Brennan, as mentioned in the episode "Born to Run". This is because Kate looks at family pictures on Tom's fridge which show a young woman with dark hair as well as a baby. Tom says the baby is called Connor, and when Kate says "he's beautiful," Tom replies "well that's from Rachel."
Tom worked as a doctor and so, if he had connections to the Hanso Foundation, Rachel could have investigated them after his death.
Basing on Kate, Tom does seem to like tough girls. He's also quite a match to Rachel as a character, as he is described as a little nerdy (which Rachel is arguably a little herself due to her many Star Wars, Alias, etc. references in her blogs/videos).
There appears to be a distinction between Lost and the Lost Experience. Lost being a television show within the Lost Experience so this couldn't happen.
However the tv show could be a documentary about a group of people who crashed on the Island, or possibly a reality show like the Jim Carey Movie - "The Truman Show".
Rachel's search for answers about the Hanso Foundation/DHARMA will lead her to the Island during Season 3. (However, in relation to the timeline, Rachel's search is taking place almost approximately two years ahead of the 'LOST present'. Also, her interaction with the writers and actors of the LOST universe at ComicCon seems to undermine the likelihood of her introduction in the show itself.)
One of Persephone's hacks says "SHE WAS A MEMBER OF THE FOUNDATION"
Would explain Rachel's motives for bringing down the Hanso Foundation, since she stated that she is motivated by her mother's death.
Rachel may know about the existence of the Island. (However, the fact that she confronted the LOST writers at ComicCon and singled out the Hanso Foundation's inclusion in the "fictional" series — but not, say, the Island or Flight 815 — makes this unlikely.)
She had a keen interest in a particular satellite photo of an island among Mittelwerk's files — i.e. more than the other photos.
In the tradition of Lost, her last name might refer to 18th Cent poet, artist and philosopher William Blake
William Blake was a Swedenborgian who was opposed to the scientific materialism of Newton. This fits with her opposition to the scientific work of the Hanso Foundation. (Science at any cost, devoid of spiritually based ethical considerations) That seems to be a major theme of the show/Lost Experience matrix.
William Blake created a character called Nobodaddy (nobody+daddy) to represent Blake's perception of the evil-seeming God of organized/institutional religion. In the poem "To Nobodaddy," Nobodaddy shrouds himself in secrecy for lecherous purposes.
Rachel may have been lying throughout the Lost Experience. She may be working with the Hanso foundation to spread the virus through Apollo Candy Bars, as she promised some major event once all the candy bars have been taken.
Alvar Hanso represents Hades, and Rachel Blake represents Melinoe, daughter of Persephone and Hades (or, in some versions, Zeus disguised as Hades). The name Rachel Blake can be translated as either "black sheep" or "white sheep," since "Blake" can mean either color. Black sheep were often sacrificed to Hades. The underworld goddess Melinoe had limbs in contrasting colors of black and white. She walked the Earth at night, bringing fear and night terrors. Rachel was given a fake Healthway Alliance ID showing the name "Melanie Walker," which could be a reference to Melinoe walking the Earth. Using the code name Persephone could have been a sign to her father, hinting at her identity. Alternatively, the original hacker Persephone could actually have been Rachel's mother. One of Persephone's epithets was Malophorus, which means "sheep-bearer." If Rachel represents Persephone's daughter, it makes sense that her first name means "sheep."