The Origins of Valentine's Day is tricky, particularly when there are 4 different St Valentines.
If you see Valentine's feet, a crippled child is there with him.
There is a decent chance that the confusion comes from one of the Valentines being all lovey, and another being good with epilepsy. And crippled children.
It's also worth adding that Valentine is one of many saints who are said to represent those with epilepsy. There's literally about 12, it's wild.
There are actually four different St Valentines recorded, but they all manage to have been smooshed into one guy and one Saint's Day.
They are often depicted with a crippled child at his feet, as you can see here. He is reported to have cured children of blindness and deafness which still doesn't answer why he's the patron saint of epilepsy.