The slope of a function is the average rate of change of the function.
The meaning of the slope is that: <em>Kayla's charges per child is #2</em>
The function is given as:

A linear function is represented as:

Where:
m represents the slope of the function.
By comparison,

From the question, we understand that:
The function models the average money charged to babysit children
So, the interpretation of the slope is that:
Kayla's charges per child is #2
Read more about slopes at:
brainly.com/question/3605446