Until Tink was trained to go potty on the pad or outside, she had to stay in her little crate if I was not home. It was big enough for her to stand up in and turn around and that's all.
Now that she doesn't soil her crate, she has a crate big enough for 4 dogs! She never soils it and I know she's safe when I leave her to go to work or for any reason. I strongly recommend crate training. It worked for us.