We had a perfect stay with our 7 months old son at Caroline's place. It's close enough to the city center for exploring Stockholm's (5min walk to station + 10min ride) best spots and also far enough for having a relaxed time with some nice cafes around (20min walk through a really nice neighborhood + parks).
Additionally cost-benefit could not be better!!
Caroline and her family are really lovely and made us life as easy as possible by e.g. sharing tips, enabling an easy check in/out, and always very fast replies.