I don't have any legal advice for you, only technical advice.
If your copy of Windows isn't the 1-use type, after you clone your drive and place it in the laptop, Windows on the laptop will detect all the new hardware and attempt to install them. Worst case scenario is Windows can't install all drivers and has old ghost drivers from your computer's hardware, and Windows can't activate. Best case scenario (if you don't have the 1-use type Windows installs), is Windows will attempt to activate and may be successful. Even then you'll still end up with ghost drivers etc.
The best option is to:
1) Figure out what Windows OS is on the laptop.
2) Look at the key code at the bottom. The hope is it's the same version of Windows as yours.
3) Once you determine all this, and let's say she has Windows 7 Home and you have Windows 7 Ultimate, and you have a DVD of your Windows, you can quickly Google on how to make a Windows 7 ANY VERSION copy. This will then prompt the installer during the initial install to choose a specific edition of Windows 7. You then choose hers, and key in the code etc. Best case scenario as with my MSI laptop is it accepts the code and activates (due to it seeing all the same hardware components). Worst case scenario is it fails to activate, and gives you a number to call. Call it and follow the prompts. Answer "one" when the automated system asks you how many computers you have this on.
BTW: I use Macrium Reflect to clone and backup stuff. Works like a charm. Macrium Reflect may be able to fix the boot issue too if you create a boot disk from it. Go to download dot com to get it.
Also, it doesn't matter if you install Windows 7, 64-bit or 32-bit, the same key code will work for both. Micro$oft likes to trick ya.
Good luck yo!