It's never easy to have a conversation about money. But I think that it is certainly worth it for your daughter to bring it up to her employer. She should learn how to stick up for herself in a diplomatic manner. Tell her to not make a big deal out of it or be accusing: say "I took a second look at my paycheck and I realized that we both overlooked the extra $5 for cleaning your kitchen" as opposed to "You stiffed me!"
If this was an oversight, than your daughter's employer will certainly pay your daughter what is owed to her. But the employer will never know that there is a problem unless your daughter brings it up.
Advice from a Moose: Think big * Spend time in the woods * Eat plenty of greens * Hold your head up high * Stay on track * Keep your nose clean * It's OK to be a little wild!