This was not what anyone was expecting.

While your dad and older siblings (plus Stephanie) were patrolling, you and Selina went to the grocery store to buy some stuff Alfred needed to make desserts. As you two exited the store after paying for what you bought, a mugger came out of nowhere with a gun in his hand, demanding money(as usual, nothing new in Gotham City).

Selina puts you behind her, so she could protect you as she got prepared for whatever this mugger was about to do. It was starting to get cloudy, meaning it was about to rain soon