Given the task definition and input, reply with output. In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: Annie Walker is a single woman in her mid-thirties, living in Milwaukee. Following the failure of her bakery due to the recession, her boyfriend left her, and she lost her savings, forcing her to take a job as a sales clerk in a jewelry store and share an apartment with an English immigrant roommate Gil and his sister Brynn. Her business failure was so painful that she has given up baking entirely. Annie has a no-strings-attached sexual relationship with the self-absorbed Ted, but she hopes for something more from him. Her best friend, Lillian, is virtually her only source of happiness.
Lillian becomes engaged and asks Annie to be her maid of honor. At the engagement party, Annie meets Lillian's bridesmaids: cynical, worldly, long-married cousin Rita; naive and idealistic newlywed friend from work Becca; the groom's decidedly unfiltered sister Megan; and Helen, the rich, beautiful, and elite wife of the groom's boss. Helen and Annie, who are jealous of each other's friendship with Lillian, take an instant dislike to each other, but Lillian persuades them to spend time together.
Who is the sister of the roommate of the woman that the bride asks to be maid of honor?