First off, congrats on getting a puppy.
Have you decided on a name yet? Please post pictures as soon as you can.
As anxious as you are to have them meet, please wait until after your baby gets through all rounds of her shots. Actually my vet said to wait 2 weeks after the last shot before exposing Gracie to other dogs, or areas other dogs frequent. When I would take her out with me I held her and didn't let her down just to be safe. I know you will be wanting to take her out to pet stores and parks and of course to meet your mom's Chi, but the few weeks you'll need to wait is a small price to pay to ensure her health. And I'm assuming that the Chi has had all it's shots too.
In the mean time perhaps you can take a blanket with your babies smell to your mom's Chi so that the Chi can get use to your babies smell. That way when they actually do meet hopefully it won't be too much of a surprise.
Good luck and let us know when you get your girl!!