That's the cover of the C64 version of the CD, so it's probably the only woman of the 8 honest men in the C64 version's story (a blonde woman, like the one on the cover)
She is unnamed in the story. However, by reading the stories of both CDs, one can come to speculations about who she is.
Most people think she's Marisa's mother (and some also go further and think she's Mima) based on a line from a random observer seeing a blonde girl come out of the house who looks younger than the woman who originally lived there. However, the title of that song is "Reincarnation", which could imply that the original blonde woman and the woman believed to be her daughter are in fact one and the same (but reincarnated to be younger)
She is stated to come from a western house from the forest in both stories. This has also led to the Marisa mother theory.
However, the only character who's house has actually been OFFICIALLY referred to as Western is Alice's.
And thus my own personal speculative answer: She's Alice Margatroid, named after Miss Murgatroyd from a Murder Mystery story (The 8 honest men story from "Dolls in Pseudo Paradise" is a murder mystery). Actually, the name of the album itself kinda gives it away, doesn't it? The only woman of the 8 honest men also reincarnates as non-human (Alice was once a human but became a youkai) and she hanged herself (Alice, who is described to look like a doll in Perfect Memento, also has Hourai dolls that hang themselves. And Hourai is one of the themes in the album)
Furthermore, the method by which she murdered the "most wary of the group" was via long distance tree-nailing. Alice is depicted to be atttempting to kill someone this way in Bohemian Archive in Red, and it is implied there is quite the vindictive murderor deep within that girl.
All of the killing is revealed in the end to all done by the most cowardly (who is also the only survivor at the end and thus the only female, and thus Alice, who's officially stated to be a coward). Likely the "clowns" were her dolls.
Of note is that the girl has trouble remembering the murders. To her, it was almost like a dream (Alice in Eirin's Bohemian Archive article ends up taking a medicine made by Eirin to remove nightmares.)
She kills herself at the end (again), before the shrine maiden sees her again (The Shrine Maiden stated by ZUN in an e-mail corrsespondence to "probably" be Reimu. Like usual, Reimu only vaguely remembers Alice. ...Reimu forgetting Alice seems to be a running gag/theme). This possibly led to a bigger reincarnation which changed her appearance to that of the younger Alice today.
Long story short, the girl on the cover is human Alice Margatroid before she reincarnated as a younger-looking youkai.
Well, that's the conclusion I came to. ~Tiamat
To the best of my knowledge, it's not a girl but the eponymous Hourai Doll (the Japanese name of the album is Hourai Ningyou according to the Wiki). The popular version of the album story makes a couple references to the doll as well.
Not saying I know for certain, but that's just my best guess.
I think she's Maribel Han, or at least a sort of pre-design of her, but there's nothing to support this in the text in the booklet so I can't say for sure either.