Mute?

So, now my precious angel, Becca, is now 18 months old. She does not speak. I thought by now she would start talking. Kaity, my older angel, refused to speak at a young age, but she COULD speak. She just chose not to. She had words, I heard them...occasionally. Now, Becca, understands when you speak to her. She understands commands. She can hear. So, why doesn't she speak? She barely says mama and usually it is when she is crying. The only other intelligable word is "that" and that is barely clear. Everything is "that". She points, grunts and cry's. At what point do I become scared? I am there. Should I be? I have always been one to say "don't worry, kids do things at different times" but I see other 18 month olds and remember my older kids then and they were gabbing away. She doesn't seem to be behind in any other manner. Am I over paranoid because Kaleb is a touch slow and needs help with is communication? He has always been able to talk, but has trouble understanding.

So, if you were me, what would you do? Start process to have her tested and maybe go into speech therapy? Or is it too soon to worry?