I think people see yellow and think "OH My ***" - but it actually looks nice. Color psychology tells us however if you put a baby in a yellow room they will be more likely to cry all the time and when you think about it all the vicious insects are bright colors (like Bees, Wasps).
Some adult reactions aren't far from crying
that's why you're getting that as a first initial reaction (my opinion)
My person opinion on flips is to remember it's not really yours (if you're trying to sell it that is) and to be safe and go neutral - introduce colors in the accessories & accents - people have to envision their stuff in the space -- how can they do that when they are slapped in the face with someone else's style. This is just my personal take - in general.
Still your mom did an awesome job -- she really has a nack for it! -- did it sale?
Should of went on Flip That House (TLC) or Flip This House (HGTV)