What is 'Tre giorni son che Nina' when translated from Italian to English?

Tre giorni son che Nina is a very old Italian song by an unknown author. It apparently concerns a young girl who has died or is in the process of dying. The Words are as follows:

For three days Nina -- Tre giorni son che Nina has stayed in her bed -- In letto se ne sta.

The slumber is killing her -- Il sonno l'assassina

Please waken her! Svegliatela, per pietà!

Cymbals, drums, and shawms -- E cimbali e timpani e pifferi,

waken my little Nina -- Svegliatemi Ninetta

so she may not sleep any more -- Perchè non dorma più

And while the doctor -- E mentre il sior dottore

goes to visit her -- A visitarla va,

dear Nina, out of love -- Ninetta per amore

stays in her bed -- In letto se ne sta.