When my 8-year old Pembroke was 5, I adopted a 1-year old. Ooffee wasn't terribly happy about that but Lulu loved her older sister and wouldn't allow being ignored. It took time for Ooffee to accept Lulu but it does work out. However, Ooffee was raised by me from a puppy, and will always be just a bit jealous when I pet Lulu. So I try to pet them both at the same time. When Ooffee is asleep, I play with Lulu. Now it's three years later; they play together and lie next to each other. If I take one for a walk, the other MUST come along. It works out.
With Ellie, it is perfectly normal for her to distrust anything new or different in the house, but she eventually gets used to it. I suspect it will be the same for Ein--they will probably be best buds in no time. By the way, we want pictures.
Love the name Ein. From Cowboy Bebop right? I was gonna name mine that, but then I decided against it. Now I have my little Pancake.
I was worried my cats would hate him, but so far they just seem confused. One of them is getting along great, but the other two are remaining cautious.
On a side note, I am moving in with some friends in a few months and they have dogs as well. Thats 3 dogs in our house (counting Pancake and he will be the youngest) so I hope they all get along. I plan on slowly introducing them the next few months.