According to the old schoolyard rhyme three things happen after two people are spotted k-i-s-s-i-n-g in a tree- first comes love, then comes marriage, then comes baby in the baby carriage.
So it follows that Disney princesses must have started a family some time after the end of the feature and beginning of the fairy tale marriage, and at least a few of them must have been terrible mothers.
Illustrator Paul Westover has given us a glimpse into the post-movie lives of Disney princesses, and it seems some were born to be moms while others face an uphill battle against their beastly offspring.
See If Disney Princesses Were Moms at CollegeHumor (NSFW-ish)