Um yes there is a possibility. But it's less than 1% bc semen need to be pushed with a force through the vagina. It needs to get all the way up to the g-spot. It's almost impossible since normally only one semen makes it to the egg. Without a push it will die within a week, and won't make it to the egg.
Im fourteen and my girlfriend got pregnant because i fingered her after i came and wiped it off with my fingers i now have a beautiful daughter named Aubree
There is a chance but not a significant one, if the semen felt cold to you. If you had fingered yourself right at the big moment and then immediately fingered her, you would have a much more significant chance of getting her pregnant, if she was at the right point in her month to get pregnant. I would take a little more care in the future. In the meantime, she should take a home pregnancy test if her period is late.