it's a personal choice- ask your aunt how long she wants them. they look fine from the picture. one concern though- you said the batting is one that needs to be quilted every 4"- doing the tied technique you have long (much longer than 4") channels running down the quilt---the ties are every 4" across- but not down- so when it is laundered there is a chance the batting will separate & have clumpy (pulled/separated) batting. i have only tied quilts with batts that specifically say good for tied quilts- and they usually have a scrim and allow a larger area- so i'm just guessing here- but it seems like you would need to off-set each row- so you have ties 4" apart in both directions- like starting the first row at 4" from edge- then the next row 2" from edge-then every 4" so those ties are inbetween the first row- then next back to the same as first---
there are probably people here who do them all the time & will tell you your's will be fine- i'm just thinking of the quilt a friend quilted -she didn't want lines across- just quilted channels down about 3" apart- after the quilt had been washed a few times she started noticing that the batting was bunching up becoming clumps with some areas bare-no batting-