I personally think you shouldn't give her the files, since that's why she hired you. I think it's kind of a slap on my face if it's done to me even though the client will pay me for it.
I think you should just tell her that as a designer, it is with regret that you have to keep the designs and she would just have to tell you what she wants within the contract rules.
If you want to appear technical, tell her that you can give her the files, but it will require selling her the copyrights, which in turn will require them to pay a huge amount for each design, but this will remove your rights over the designs. Tell her that because you will no longer be able to place these in your portfolio or reuse the elements in the design, you will have to charge her more for it, although I think this option seems rather intimidating and passive aggressive.
If she insists, then I suggest giving her the files in minimal detail (maybe in one entire layer or in five layers and then in low resolution, or with a watermark, or something. If she complains, give her the first reason I stated, or make something up :)
I hope she doesn't insist, and I hope she just lets you design them within the contract rules!
All my hopes.