<human>: Can you give me the gist of the text in a nutshell?

As with many stories, this one happened not today but several years ago. 

So my girlfriend and I have always been the type of people to embrace their inner child no matter how old we get. As such, when we decided to get a couple of piggy banks we decided to go with these cute matching stegosaurus ones we happened to see at Target. 

Some time later, we had both accumulated enough coins in each to warrant a visit to a Coin Star. The one in Walamart happened to be the closest and while I was a little apprehensive carrying our piggy banks into the place, my girlfriend was insistent that it was fine.

So we get there and begin the process of shaking our little dinosaurs and depositing their innards into the machine for cold hard cash. Halfway through this process, an elderly woman gets the attention of my girlfriend and whispers something in her ear while simultaneously putting something into her hand. 

My girlfriend looks down her hand before looking up and saying, "Oh my god, no! It's okay!"

"No, no, no," the old woman says as she's practically running away. "Keep it, keep it!"

The woman continues to make a hasty retreat until she is out of the store and my girlfriend turns back to me and my waiting question of 'uuuh, what?'

"She gave me twenty dollars," my girlfriend says, holding up the bill for me to see.

"What? Do we look poor or something?" I ask. 

My girlfriend is quick to dismiss that. What the old woman had whispered to her was: "I know you stole those from your babies." 

Seeing as we had no kids, we felt pretty bad about keeping the money, but the old woman had been quick to leave and there was little chance of her having second thoughts and coming back. In the end, we used the money for almost free dinner.
<bot>: Bought kiddy-looking piggy banks and when we went to turn in the change for bills got an extra $20 from an old woman who thought we stole them from my imaginary children.