I take the first one at 30 but she will be limited on talking, the next one or two around 38 they can talk a tad more and next 40 years old but she will need to be gagged too because she doesn't know enough yet. Now the 45/50 year old might be best as they generally know when to shut up.

....but all in all I will keep the one that looks at me and smiles everyday and Salty will keep his DDD too. You can't beat the home run of the Lady that makes sure my pipe, smoking jacket and slippers are ready when I walk in to our house. DDD does the same for Salty.