What happened next would bring together two Delaware County families - one from Upper Darby and the other from Broomall - by way of County Tyrone.
And Alba, a junior at West Chester University, would make sure that Mohan beat the odds.
"It had been a terrible week," said Mohan, 52, who emigrated from Ireland 25 years ago.
Earlier, she had boiled water for tea in a saucepan and forgotten it.
"I nearly set the house on fire," said Mohan, who coaches ladies' Gaelic football, a sport that combines elements of soccer, volleyball, and basketball.
So Mohan went to Macy's to buy a kettle that whistles.
In her wallet was $1,000 her sister had wired her to pay back bills incurred during a Christmas visit.
Mohan purchased a black teakettle, but when she got home, she realized she didn't have her wallet.
"I jumped in my car" and drove back to the mall, Mohan said.
Minutes earlier, Alba and her mother, Wanda, a registered nurse, had been celebrating Angelise Alba's 20th birthday with a pasta dinner at a Cheesecake Factory.
Alba, who is majoring in communications studies, spotted a wallet on their way to their car in the parking lot.
She picked it up, and the mother and daughter set off for West Chester, where Alba lives on campus.
In the car, Alba began looking for a name and contact information. What she saw was a whole lot of green.
"I thought, 'Wow, that's a lot of money. Someone must be freaking out by now,' " Alba said.
Then she found Mohan's license. Alba Googled her, found her on Facebook, sent a message, and left a voice mail on her phone. She gave the wallet to her mother and went to her dorm.
By then, Mohan was viewing video in the mall security office. Officers showed shots of her leaving the store with the wallet. She must have dropped it in the parking lot.
Mohan reported the loss to police and drove home. The next morning, still upset, she went to get an MRI for a bum hip and left home without listening to her phone messages.
"All kinds of things were going through my mind," Mohan said. "I was lying [in the MRI tube], I was crying." The people working the machine asked her to please stop shaking.
When she got home, she retrieved her messages and heard Alba's voice.
"Thank God for that kid," Mohan said.
She drove to the Alba home in Upper Darby. Angelise was at school, but Wanda Alba was at home.
"Everything was in the wallet," Mohan said. "I gave her a big hug."
She also pulled out $100 and insisted that Wanda Alba give it to her daughter.
"I was happy to help her," Angelise Alba said of returning the wallet. "I didn't think it was that big a deal, actually."
Her mother is proud of her.
"There wasn't a moment's thought about keeping it," Wanda Alba said. "Her concentration was, I need to find this lady and give her back her money."
Mohan then insisted on sharing the good news of the student's good deeds. She wrote a letter to the president of West Chester University to tell her "that this kid is amazing."
That's not all.
Coincidentally, Alba, who is working toward a career as an event planner, will be traveling to Ireland this summer for a semester abroad.
Mohan's sister plans to meet Alba on the Emerald Isle, Mohan said, adding, "We're going to give her any help we can."
Contact Kristin E. Holmes at 610-313-8211 or firstname.lastname@example.org.