We tried adding a girl when Sophie was about 1 year old. We added Hazel who was slightly younger and although in the beginning they played well together it eventually turned bad. Hazel became very aggressive with Sophie with everything from toys to being on the couch. We started to really be concerned with Sophie's safty. It was hard but after some time we realized it wasn't going to work and made a gift of Hazel to my niece. Both seem happier being in a one dog household. There may be another yorkie puppie who would work out great and be friendly to Sophie but we don't want to take the chance of it not working again and are happy the way things are now.
