Thats a hard decision, i had a yorkie called Boo-Boo and he was a strong character,he was a month younger than Duchess and he came into our home a couple months after I had Duchess.He bullied her and she turned into a petrified little girl,she wouldn't play or eat.In the end I had to re home Boo-Boo and Im pleased to say Duchess is 100% happy and confident now. I would deffinatley go for the bigger girl