have to disagree with those who are saying it is normal. sorry, it is not normal. normally, they are saying more by that age. I speak as the mother of 2 autistic children who were practically mute until about 5! and your second post added to the alarm bells.
When i first started saying i thought there was something wrong/different/odd about my eldest, people said oh, no, dont worry its normal, its all normal. well, it wasnt. and i have said to some of these people 'you said it was normal' do you know what they said - i didnt want to worry you, i wanted to reassure you.
that is no good. if there is a possibility of a problem, then to try to say there otherwise because you want to be reassuring is not helpful. you can only deal with things by facing them head on, and that means saying i think we have something here that needs investigating.
it may well be that she is a late talker, but i would really be asking questions. the site i linked to was very clear that it does not neccessarily mean theres a problem, but it could point to something.
it is always better to get it checked out. if there is nothing, then no harm no foul, right? but if there is something then good, because early intervention is vital to achieve the best results.