Who is Liza from Notes from the Underground and what is their importance?

Liza is the woman the writer meets in the house of prostitution. Liza confides in him that she's from Riga, where she lived with her parents. She says that she hasn't fully committed to becoming a prostitute but that she already owes money to the madam of the house. She doesn't say how it is that she came to be in that position, but the writer berates her for her decision. He rants for some time on the benefits of living at home and the negative points of living as a prostitute.