How does Ina view her sister's role in the family in the novel, Miss Lulu Bett?

Ina does not consider her sister an equal; rather, she pities her unmarried sister, while at the same time relishing the fact her sister has nowhere else to go, because it makes Ina's life easier. As she says at the end of the play, when she realizes that Lulu really is going to leave for good, "Dwight, you've simply got to make her stay. When I think of what I went through while she was away . . . everything boils over, and what I don't expect to b-b-boil b-b-burns." She demonstrates her true feelings about Lulu with her next lines: "Sister, how can you be so cruel when Dwight and I—." To Ina, Lulu is a cook, a maid, and a babysitter, but little else.