Of course you should encourage her speech - she clearly enjoys it.

I read somewhere that kids who start speaking 'early', like your kids, are good at picking up other languages, now and in later life.

For comparison, my DD was nearly 2 before she said very much. She certainly understood everything, and communicated in her own way, did a few signs. And DS who is now 20 mths is just starting to parrot words.

Don't back off - actually, it probably isn't something you have control over! Enjoy the marvellous journey.

Teach her some songs, play with it...sounds like you all have lots of fun together.