The guilt of not knowing - Airport formula and diaper scam

How do you deal with the guilt of not knowing whether you sidestepped a scam or denied a person in crisis aid?

Me, the wife and our 8 week old made a trip back home. Father in law was picking us up, and this woman appeared out of nowhere in the parking lot of the airport. She's got a ratty phone and starts talking about how she's not a beggar but desperately needs money for formula and diapers. She's just got out of an abusive relationship 2 days ago,I would be giving them dignity, good Christians, Yada Yada.

No kid in sight, and when FIL questions this he gets ignored. I have 0 cash on me, but this is no issue, she asks what bank I'm with and immediately knows the best way for me to send her cash. She can't figure out what her number is though, so I should just send the cash(100 usd) to myself and give her the code.

At this point I can't get past these red flags, so to get rid of her I send the cash, then cancel the transaction as soon as she left, basically with tears in her eyes at what a good person I am.

I'm like 65% sure this was a scam, but the not knowing is gnawing at me. There is so much poverty around me and I can easily afford 100 usd. What is the answer in a situation like this?