Toddler speech development

My toddler is 19 mo and she does not seem to like to open mouth to talk to us. She does called us mama and papa without being prompt. But for other things like want snack, see car etc she will only point at them but does not speak to tell us. She also understand what we are talking to her, but just doesn't want to speak up talk to us. Is my toddler having speech issue? I am getting very worried for her.