It was about 30 images, though I'm planning on adding more and training again sometime. Either that or splitting it up between when her hair is short and when it's long, as it really changes how she looks.
I'd recommend increasing the network dimension to at least 64, if your VRAM can take it. I can do 64 with my 12GB card. At least for people, I've had better luck using a token that's a celebrity. I'm not sure how to try that with my dog - perhaps just "terrier dog" or something.
I should have been clear - I'm using the Prodigy settings on that page, not the Adafactor one. You set the learning rate to 1 and the scheduler to cosine, but the real learning rate is figured out by the optimizer.