Help with translation please: Baby / Granddaughter.

what is the polish word & pronunciation for baby?

it may depend on the context.
Is is a little child? A girlfriend? Other?

baby is my granddaughter

baby (newborn) - niemowlę
baby (dear child) - dziecko (child), kochanie (dear), drobiazg (informal)
granddaughter - wnuczka, wnusia (diminutive)

That's all I can offer without an exact context.

as in saying "my granddaughter" or "hi granddaughter" can you possibly help with pronunciation?

Others may use better transcript, so my feeble attempt would be:

my granddaughter (speaking about her)

Moja wnuczka - (pron. moyah vnootchkah)
Moja wnusia (affectionate) - (moyah vnusha)

hi granddaughter (speaking to her, addressing her)

Wnuczko - (pron.vnootchko)
Wnusiu (affectionate) - (vnushoo)

As I am about to be a first time babcia I wanted some idea of the words. I have only maybe a 10 word polish vocabulary which are all relating to relatives. Thank you for your help

grizhun, you can always check pronunciation here, it's really good:ivona.com