Mfl- I completely appreciate the emotional mental spiral you are in. You want what is best for Coco, what is best for you, and you really don't have enough information. You made a start by posting here about what is involved in breeding, now it's time to remove more questions. The only way I have ever found to get past emotion when making this sort of decision is to gather all the information I can.
I would also echo the suggestion to go see your vet. Ask about spaying. Ask about breeding her. I would gently suggest that if the answer is that it is not possible to spay her, it is likely inadvisable to breed her, as complications do happen, and sometimes emergency spays are necessary.
Dogs should be bred not just because they have excellent temperament, but also because of their excellent physical structure. Ask your vet what flaws your dog might have. Is her bite good, her back and her legs good, her heart good, etc?
Also, from a financial perspective, I would also ask the vet about the costs of a litter. How much for emergency services if something goes wrong, for shots and deworming and whatever else is required (I honestly don't know the details, but was pretty shocked when my dog's breeder told me how much the litter had cost her in vet bills). Also check the list Johanna posted--many of those things are not cleared genetically, and you would want to see similar testing from the stud.
Do you have time for a litter? I know newborn puppies require an awful lot of care, and raising and socializing puppies is a big job when done right. Maybe take a look at Puppy Culture. Do you have 2-3 months to devote to puppy care?
From an emotional perspective... I can never see myself breeding a dog. It's WAY too much risk and heartbreak if things go poorly for mom and pups (even years down the line). But you need to make that decision for yourself. Breeding sure isn't for the faint of heart.
All the best for you and Coco