I have absolutely LOVED having two!
Franklin was around 8 or 9 months when we added Maggie (who is 3 1/2 years old). I think the general consensus is that a male and a female get along better than two of the same sex as sometimes they fight for dominance. If you're worried about the boy having someone to "rough house" with, no worries! My Maggie can beat up Franklin any day. Just make sure they will be around the same size full grown so you don't have to worry about injuries or anything like that.
But really -- getting Maggie was the best possible thing I have done for Franklin. He loves having a playmate, and I feel much better about leaving him at home knowing he has a warm body to snuggle with.
Go for it!
