Thanks everyone. I'm determined to grow her coat out. She's just now getting enough of a topknot to keep it up. I've read that it's better to stick it out so I can keep the hair out of her eyes better. She lets me groom her and even manages to leave in her rubber band. It will be easier when it gets longer, I know.
As to the stains, yes they look better than they did. It is definitely from her eyes and mouth both. I switched her to a raw diet not long after I got her. It has gradually improved but no signs of completely going away. A month or so ago a show groomer suggested I remove all red meat from her diet as that can also contribute to the staining so she's on chicken and turkey now, no beef. Her teeth were cleaned by the rescue back in April and they still look good. I started her on Angel Eyes as a last resort after diet didn't fix it. The maltese I had before had NO staining at all (same house, same water supply) so I hadn't even really considered the water could be a problem, especially since she came with the stains. I only recently discovered I could hide her water bowl in the bathroom to keep the bigger dogs out of it (since they'd rather drink her thimbleful than their own big bowlful) so bottled water might be an option now.
What is on her chest is what has grown out from above. It definitely is still under her eyes but it doesn't really show in the photo. If you'll notice what is on her forehead, that is the hair that has been in her eyes when it comes out of her topknot. I'm still experimenting at this point and I know a change of diet can take months to completely make a difference so it's a slow process.