Hi,
Given your situation, I would think rescue is the perfect answer for you. Why? WIth a rescue you know exactly what you are getting. The dogs are evaluated so you can choose one that is good with children of the age of yours and a dog the size of yours. A puppy is a wild card. Dogs do have certain predispositions towards dominance, etc. Of my four personal boxers I have had, all being rescues... the adults were so, so much easier than the puppy. The dogs came into my home at the ages of 8 weeks, 8 months, 4 years, and 5+ years. I also had a 12 month old foster that was lightyears ahead of the puppy in manners! Rescues most always, and you can choose one that is.... housetrained, child loving, obedience training (basic usually.) Puppies teeth, go through many lessons, and do not know how to treat children.
Rescues to not adopt out dogs into homes where they will not thrive. Anotherwords, they wouldn't give you a dog that might not do well with children. If a dog is not good in certain situations you would know it beforehand. Most rescues are lovely pets who had the unfortunate experience of having a irresponsible owner who never committed to owning the pet for a lifetime.
Good luck finding the newest member of your family,
Ashlie