I have a test where I am given the following article, what is an answer for the question: Who is the investor's niece? ?

A prologue introduces the Nickelbys, country gentry who enjoy a comfortable life in the Devon countryside until the father dies and leaves his family with no source of income. Nineteen-year-old Nicholas, his mother, and his younger sister, Kate, venture to London to seek help from their wealthy, cold-hearted uncle Ralph, an investor who arranges for Nicholas to be hired as a tutor at Dotheboys Hall in Yorkshire and finds Kate work as a seamstress.
Nicholas is horrified to discover his employers, the sadistic Mr and Mrs Squeers, run their boarding school like a prison and physically, verbally, and emotionally abuse their young charges on a regular basis. He eventually rebels and escapes, taking with him the crippled young servant boy Smike. As they journey to London, they stumble upon a theatrical troupe owned and operated by Mr and Mrs Crummles. They cast them in a production of Romeo and Juliet, but despite a successful first night and the couple's invitation to stay, Nicholas is determined to continue their journey to London after hearing that Kate is in trouble.
Nicholas discovers his sister has been subjected to humiliating sexual harassment from the lecherous Sir Mulberry Hawk, a client of their uncle, who has encouraged the man to seduce his niece in the hope that she will succumb and thus cement Hawk's business relationship with him. Nicholas confronts Sir Mulberry and his uncle, renouncing the latter. 
Nicholas is reunited with his family, who welcome Smike as one of their own, and finds clerical employment with the kindly Cheeryble brothers, who offer him more than double his previous salary. While thus employed, Nicholas makes the acquaintance of Madeline Bray, an artist who financially supports both herself and her tyrannical father, as her father gambled away his fortune and that of his late wife.

Kate