I am also skeptical as RossLee. The honest thing to do would be to stay in Canada and LEAVE as soon as your baby is healthy enough to travel, but basically you are saying that you want to stay here for good. As you say "no body want to travel and get sick and have 80k bill in the head. and no body want to have a premature baby." and nobody wants to leave their country just because of a very terrible situation.
My advise would be that you stay here until your baby is healthy enough to travel and then leave the country for good (most likely to Italy). I sincerely don't believe that the hospital expects you to pay, as you are a visitor, the situation was exceptional and unexpected (they must have been well aware that you are from Venezuela and 80k are the savings of a lifetime). You should have no problem extending your visitor status as you should have in writing your baby's diagnosis which state she can't travel for the time being.
If the price to pay for your baby being healthy and with you is to be inadmissible to a country you didn't even had the intention to immigrate to (neither you have close family), then so be it.
Other options I have seen in emergency situations is that the parent leaves the country and goes back to where hew works. Then he sends money to their family until they can travel. This option might be better for you as the one in debt is you and you are the one who wants to work. Of course this has been done in situations quite different than yours. I understand that you want to be with your family but extraordinary situations need extraordinary sacrifices.
God bless your baby and your family.