Wow that was a story to bring a person to tears..all I want to say is I agree with the others.. I took in my first three as adults and omg.. we loved them so much.. and still miss them.. for some reason they all seemed to appreciate us far more the when we get a puppy and just spoil them.. they respected us and would do far more for us to please us.. not sure why but they did...especially none were trained..

some breeders do not train there dogs..
I have not had a dog or a yorkie.. so we learned and we learned to tain well.. it was different then training babies.... we learn to do it different..
I know this female really needs a home..and I am just sharing our older dogs..keeping time here.
Well we finally had our first puppy and omg...I had my first litter of three.. and lost two to cleft pallet.. so what was left was one boy..I so wanted to keep a girl..but we had this little guy sleeping with us at 4 weeks old.. he would cry so much being left alone at night.. we got him a tiny harness and hook him into it.. and hooked him onto the headboard of our bed.. and other then him making a mess in the bed.. we fell in love.. he was the best dog I had.. he was my baby, my life and when I look back at my disappointment that I had no girl.. it makes me sad.. for I lost him at 5 years old when my vet gave him the wrong shot and killed him..
I am not sure what your thoughts are now or what you have decided on.. but maybe this breeder will give you the 5 year old at a greatly reduced price since she is this age. and much harder to find a home for.. get the boy.. and have two.. you might want to ask her if you can try this out.. but maybe with her and a baby.. things will be ok.. she would train baby to let her be top dog and yet he would fit in.. we all have top dogs.. but that does not mean we cannot have more then one.. I might add I am the top dog.. but they think there is a top dog also..LOL
something else for you to think of.. one is sometimes lonely.. then as the boy is older and the female is not wanting to play you can get your girl then.. to carry on with the baby always used to having a sister or brother at home..
Anyway thanks for sharing your story.. you will know within your own heart.in fact you may end up with breeding having what you want/need from reading this thread and you just might find your baby...good luck.. and please keep us updated on your decision...big hugs to you...anne.