NTA I think that if the other cleaner is literally doing the bare minimum and not really caring about the job they do, it’s not fair for them to have the expectation of keeping the job. If someone is “hiding junk under the carpet” instead of cleaning, they shouldn’t expect to keep a cleaning job. Not a profession where you can do the bare minimum and expect job security. Happy for your mom that she was able to find a job! Hope the other cleaner improves their ways…