Don't forget Gerould was writing in 1932. French versions may have come to light since then. As Gerould states, by that time only the Scandinavian and British ballads had been published in a systematic way.

Will send Crawfurd and Grieg Duncan shortly.

I haven't time to follow these up just now but in my foreign ballads index are the following relevant titles
Den Lillas Testamente (Swedish)
The Child's Last Wishes
Where have you been all the day (Irish)
O Dear Son of Mine (Welsh)
The Child's Last Will (Howitt)
The Child's Testament (Heywood)

Erich Seemann 'European Folk Ballads' 1967 pp80-89 should prove useful.