enhancement - autofill age range for kid activity.


**Is your feature request related to a problem? Please describe.**
It's not realated to a problem

**Describe the solution you'd like**
In the activities page, it would make sense if it automatically sets the activity age range based off of your child.

**Describe alternatives you've considered**
Custom specified age range would also be a cool enhancmeent

**Additional context**
n/a