(Click to zoom in)
No matter your age, or personality, this will sting, so I am proposing an idea for the option "Take in".
When you click "Take in" theres a 30% chance the cub wont make it, with the usual text showing. If you're the lucky 70%, a random abandoned cub from the tree with a Neutral, Kind or Good personality between the ages 5-7 months will be brought to your Unsorted den. The cub will have 100% hunger and 0% mood.

Just another thought that might make the event.. less sad.