A special note should be made of speech problems in children. First, some toddlers and preschoolers do not talk clearly, or stutter and stammer, talk too fast, use words incorrectly, or have other difficulties with the production and flow of speech. Unless your child's speech is unintelligible to almost everyone, it is a mistake to be overly concerned. Do not make a big deal of it or try to get her to make her speech intelligible. Rather first make more of an effort to understand what she is trying to say.
Even five- or six-year-olds have occasional problems with speech. By then, it is acceptable to gently encourage your child to slow down and speak more distinctly. Even so, it is a mistake to make a big issue of the problem. Ask other people if they have any difficulty understanding your child. Ignore the problem for a few months to see if things get better. If your six-year-old is still having difficulty, check with a qualified speech and hearing therapist.