How is Cocoa acting? Is she still throwing up? And, is she eating her normal amount, now?
If you only have one cat, you can also cover the litter with plastic wrap and push some of it down into small indentations like the size of a man's fist, and when she goes, you can just dip the test strip in the collected pee.
I just a cleaned out Fancy Feast Appetizer container or other small plastic container to put under J.D.'s tail when he's going. I wait until he starts to go, and then put the container under his tail. Other people use soup ladles, but I think those are kind of big. Good luck.
If she's still throwing up or inappetant, then I think she needs a visit to the vet.