Hi Leslie, I'm so sorry for the loss of Ritz's littermate. No matter how young they are or how short of a time they've been with you, it is the hardest thing to go through. Well I have a couple suggestions for you. One would be to check FREQUENTLY at your nearest shelter. We do get pure bred small breeds in but they go like hot cakes. If you make yourself known in the shelter and they know what you are looking for, they may be willing to help you out and call you as soon as they get a little puppy in that fits your requirements. Of course you never know how long this could take.
Another option is a puppy mill rescue group. There are a lot of these that are geared toward small breeds only. A lot of them are adults but they do also get puppies. And they are willing to work out transportation. I'm going to look around my bookmarked puppy mill websites tonight and come back and post some links for you.
You could also contact a breed specific rescue and see if they have any rescued females who are pregnant.
I think you're making the right choice by wanting to rescue. It is the most rewarding experience in the world and I'm sure your friend will be so happy with her surprise. The only problem you may come across is most shelters and rescues won't allow you to adopt a dog as a gift. Too many living gifts turn out to be unwanted. But since we are sure your friend will love her bundle of joy, you could just pretend you were adopting the dog yourself to avoid the hassle they'd give you about adopting as a gift.
I will post some links in a little bit!
Shiloh, Reece, Lolly, Skylar
and fosters Snickers, Missy, Magic, Merlin, Maya