What matters most is your individual situation, as everyone has said. : )

Does the gender of the dog make a difference to Ginger? Does the size make a difference to her? What about you... what do you want in a dog? What size do you prefer, and what size do you feel you could best handle? What personality? What energy level? Make a list of what you want, and what you need in a dog.

Personally, I have not adopted a dog over 2-3 years old... but, the great thing about adopting an adult dog, particularly one in a foster home, is that you can accurately judge their temperament. I don't see any reason for a dog that is 5-6 or older to have any more issues than if they were 2-3.

IMHO, if what you want in a dog is mostly regarding their individual temperament, the best place to look is in rescue. You can literally find the perfect dog, for your situation, without much searching at all. I did, within a few days. Not to mention, you will be giving a home to a dog in need of one, which feels really good. The best advice I can give you is to research, plan ahead, take your time, be realistic about what you can handle in a dog, and make sure you are FULLY prepared to handle another dog; personally, I feel that 2 dogs is at least 3x the work, but totally worth it for me.