I have hand quilted an all over meander. It was rather structured as it was a stencil but still gave that effect. Had flowers and leaves as well as the all-over 'vine'. It really wasn't too bad to do but not sure that I'd do that for the quilt you are making. I agree with the others that suggested a cable in the white strips. Then again, I'm partial to cable designs. I'd probably also treat each block with a different design or several simple ones rotated throughout the quilt. Those little girls are tough! Too old for baby stuff but you don't want to be too 'adult' either. The only request I got from my, at the time, 8 yr. old niece was 'no hearts Aunt Kim'! Did a combo of the above meander in the body of the quilt, but it was pinwheels kind of in a 'kite tail' pattern so it lent itself to that (at least to me!) and then cables in the borders.