Hopefully you have an gleefully excited puppy that will grow out of it quickly.
But just in case..... I had a rescue that had a horrible problem with submissive urination (murder on the couch and carpet when she was jumping everywhere). Through a lot of research and good resources, I discovered that often in the wild, submissive dogs urinate to show respect for the dominant dog and to show (in the wonderful smell of their urine) that they mean no harm. She did this for my husband, and if he would react "in a good way" to her to calm her down, it got worse - trying to reinforce her desire to please him and not challenge him.
So as Erin suggested, I would also suggest while you're waiting for her to outgrow this, keep an eye out to make sure that you don't suspect submissive urination. That way, you can start training her on confidence building right away. But hopefully it's just a goofy puppy thing. I think I'd put some fancy pants on Lucy.
