Good With Dogs:⬛⬜⬜⬜⬜⬜⬜
The breed standard does not allow for a Staffy to have light eyes. In the show ring, that would be a default and the dog would not go on to another show. For people whom are not breeding to better the breed through the set standard put together by the AKC, UKC, or CKC, ect. then the eye color 'green' has been known to show up in light coat colored dogs.
If you have COPD and have problems with dog hair/dander, then I would reconsider the Staffy breed. They are not considered a hypoallergenic breed of dog. The breed sheds on an average scale and the short hair stick into furniture and clothing quite easily. No matter if it is the 2-year-old, or the 3-month-old, bring your Cockapoo with you to meet the dogs. The two dogs will tell you which one's get along the best. All interactions between the two dog should be supervised at all time because of the size difference of the two dogs. As well as Staffy's are hard players and can be pushy with other dogs.
Every dog is different. That is the first thing you must keep in mind with you when it comes to meeting a new dog. The reason why there are standards for purebred dogs is so that a potential owner can access that information as to how the dog will most likely act as an adult. However, every dog has their own personality, which is groomed as the dog grows from puppyhood to adulthood.
What you should do is take the Chihuahua with you and once the dog has met you and is comfortable with you, then allow the dog to meet the Chihuahua. All interactions between the dogs should be supervised at all times because of the size difference between the two dogs when/if you take the dog home. As for energy, again, every dog is different just like people. Some are more energetic than others, same goes for dogs. But that does not mean he does not need exercise. The A.S.T needs about an hour to an hour and a half of exercise a day, so keep that in mind. It may be less if he is less active, but an hour at day is best. A tired dog is a good dog.
The main thing you have to consider when wanting to bring a new dog into the family that already has a resident dog, is why? Once you understand why you want another dog, the next thing is to look at the resident dog and see if he/she even likes being around other dogs, or just tolerates other dogs. The American Staffordshire Terrier is a people oriented breed and is known for dog aggression if the dog is not socialized properly. You know your dog. You know what dogs she plays with at the dog park or with friends' dogs. Use the information you have by knowing your dog and go from there. But first, consider fostering before adopted or buying, in case things do not work out. This way if they don't, then you don't have a dog you need to find a new home for. Contacting your vet or a local trainer is also a good idea, they can help you match a new dog with the one you already have.