IMO, seed stitch does not need to have the first slipped and then purl the last as you are doing. Just do the seed stitch as normal. Give this a try and see if it helps. If she did not do what you were doing, it will throw things out of whack. And (if you don't know) there are 2 different ways to do seed stitch depending on the amount of stitches being used.
Correct- in fact it makes it look worse as the stitches don't line up correctly.