Which preposition to use with mysie

in Occurrences 1%

wee Mysie in her bosom.

on Occurrences 1%

It was plainly true; the pain in the breast, telling its urgent story to a bewildered, ruined brain, was misread and mistaken; it suggested to her the uneasiness of a breast full of milk, and then the child; and so again once more they were together, and she had her ain wee Mysie on her bosom.

Which preposition to use with  mysie