Leo Kottke also recorded Paul Siebel's Louise, years ago. But there's a much older Louise song (my grandmother's name), I think that Maurice Chevalier sang it. This really isn't a folk song but it's a sweet, happy little thing:

Every little breeze seems to whisper Louise
Birds in the trees seem to twitter Louise
Every little rose tells me it knows
I love you, love you.
Every little beat that I feel in my heart
Seems to repeat what I felt from the start
Stars in the sky
Twinkle that I adore you, Louise

(I'm not sure this is in the right sequence, and I'm sure I've left some out. This is a song for skipping around your kitchen to, or skipping down a sidewalk on a summer night.)