two questions

[wowenglish1]

I have two questions.
1. I would like to know the meaning of "You just keep smiling and thank God she's not yours" in the next writing.


2. I would like to know why the next writing is a joke.



My baby-sitter knows not to bring my one-year-old daughter, Ami, into the supermarket where I work. One glimpse of me at the checkout counter and Ami will scream until she's in my arms. But one day, with the fridge empty, Maxine had no choice. And, as predicted, when my daughter spotted me, her wailing could be heard throughout the entire store. Unsure what to do, I just smiled and continued scanning a customer's groceries. "That's right, honey," said the woman I was waiting on. "You just keep smiling and thank God she's not yours."

[Raymott]

I have two questions.
1. I would like to know the meaning of "You just keep smiling and thank God she's not yours" in the next writing.
The child is hers, but the customer doesn't know this. The customer is complimenting the worker on her ability to tolerate other people's insufferable children: Keep smiling, be patient, and console yourself with the thought that at least the child isn't yours.

2. I would like to know why the next writing is a joke.
It's a joke because the customer assumes the child belongs to someone else, whereas it is actually the worker's child.
The customer is also inadvertently insulting the worker by saying "Thank God she isn't yours", with the implication "Who would want a child like that?!"

My baby-sitter knows not to bring my one-year-old daughter, Ami, into the supermarket where I work. One glimpse of me at the checkout counter and Ami will scream until she's in my arms. But one day, with the fridge empty, Maxine had no choice. And, as predicted, when my daughter spotted me, her wailing could be heard throughout the entire store. Unsure what to do, I just smiled and continued scanning a customer's groceries. "That's right, honey," said the woman I was waiting on. "You just keep smiling and thank God she's not yours."

PS: Is this a Reader's Digest joke?