Hi, my daughter is almost 6 and still talks like that. BUT, she has been diagnosed with autism. She was also raised in a house with only 1 language. Generally I would say this is a sign of a delay, but since she has been regularly exposed to 4 languages I'd lean towards no. I bet that if you go down to 1, maybe 2, languages you will see a lot of improvement. Just to be safe I would also take her to see a speech therapist.