Well I probably wouldn't be able to do it (sorry) because I hand sew all my stuff and you probably don't want that but here's an idea I tried that works great. You get a onesie and reconstruct it into a shirt for your yorkie. Then you could do what I did for my cousin's yorkie, and add tulle (that tu-tu material) or sew some more fabric w/ ruffles to make it a little dress.
Here's the link for how to make the shirt I explained
*warning, uses the word B***: BASE AESTHETIC: Craft-minded; A Guide To Puppy Stitch and Bitch Fashion
And I also LOVE this hoodie, which is also baby's clothing, so you can use to tutorial above to make it!
Maintenance Mode...
**Oh yeah, before you buy the onsie or w/e, make sure you get your dog's measurements and see if it fit her. You can find cheap cheap onesies and other baby clothes at your local dollar store, also..
*EDIT*Soo Sorry for the graphic language, didn't know that was there!!!!