Where do freckles come from ?

[Queen B]

I have freckles, around the nose and the cheeckbones - not so noticable (that kind)
My mom has freckles ,lots and lots, full face (+upper body) (this kind).
My man has some freckles, more sparse but all around face+upper body (this kind).

[Ayetooey]

Ireland, since they're the people I see with freckles.