Nellie had no choice but to appear timid. There were no unions to protect her. I am sure she wanted to talk back or to say she was tired. I am sure that she wanted to do something to Eddie Ryland too. In addtion to providing for herself she had to send money home.
I do not think that it is strange that Nellies Uncle was working in the book. At some tine the money would have run out. His job seemed to be that of a day laborer rather than a permanent job.