At first, Mrs. Beatty, the no-nonsense lunch lady, doesn't seem to care what happens to Henry. But over time, he recognizes that although Mrs. Beatty is gruff, she cares about Henry and Keiko and will protect them when necessary.
After Keiko goes to Camp Harmony, Mrs. Beatty defends Henry from school bullies and then gives him a chance to work with her and find Keiko at the internment camp:
"I never liked him anyways," Mrs. Beatty said as Henry went back to serving the last few kids in line, who looked delighted to see the school bully taken down a peg. "You want to make some money Saturday?" the stout lunch lady asked.
"Who? Me?" Henry asked.
"Yeah, you. You got other work you got to do on Saturday?" (30.24-26)
She's not offering him a job because she needs him there; she's doing it so he can find Keiko and spend some time with her. Mrs. Beatty isn't the most effusive person, but she definitely has a heart. Without her help, who knows whether Henry and Keiko would have been able to stay in touch at all.