Note the poster says straight up he at least implicitly agreed the other owns 100%, and that he did the project as a learning experience.
On the other hand, don't sign anything like this, there's absolutely no upside, plenty of gotchas (albeit, at least if your country's contract law is like ours, it'll be unenforceable because of a lack of "consideration", see the "no upside", but that can be expensive to prove), and no previous agreement to do it.
Keep your end of the bargain, deliver your stuff, and let her have a learning experience about how far one can take a dead body of code and her attitudes towards the creators of such.
Not to mention probably not getting the IP rights locked down. If you have no agreement on that, mark it copyrighted by you, and give it to her like that.