In Chapter 24, of "To Kill A Mockingbird," the ladies who belong to the Macomb ladies church group are all together talking and Mrs. Merriweather is talking about the problems she has with Sophie. "Merriweather says that the only reason she keeps Sophy as an employee is because the depression is on and Sophy needs the $1.25 per week that she pays her."
Mrs. Merriwether is a hypocrite. On the one hand she commiserates with "those poor Mrunas" and pledges to help them, but she keeps Sophy in virtual bondage, ordering her about at will. She speaks in a very deprecatory manner about Sophy: "It's never entered that wool of her that the only reason I keep her is because this depression's on..." She acts as though she is concerned for Sophy, but she cares not what happens to Tom Robinson.
When she mentions the "going's on" in town that she feels unsafe about, Mrs. Merriweather is probably glad that she has Sophy, who would know any trespassers. Afterall, without Sophy, Mrs. Merriweather would be alone and vulnerable.