[savagedata]

Was PayPal trying to verify your identity or that you know your recipient's identity (who's coincidentally your mother)?

I'm surprised if PayPal expected you to know your recipient's birthday, but "What's your mother's birthday?" would be a common question to verify your identity. They should have moved on to another question if you had a moral objection.

On the other hand, scammers will often ship goods to a nearby address and pick them up off the porch, so verifying that you know your recipient might actually be a fraud countermeasure.