4yr old who's in speech therapy, yet speaks nasily

Hi,  my 4yr old has been in her private speech therapy for one yr now.  At first it worked magically, helped my daughter progress so much in few months.  But recently my daughter's speech is not understandable, very nasily.  It is extremely fraustrating for both of us.  She speaks so fast, her words breaks down in the midst of the sentence! Any suggestions will be greatly appreciated.

[Kevin Kennedy, Ph.D.]

In addition to the ongoing intervention of the speech/language clinician, she should be evaluated by a Pediatric ENT specialist.