How to restore to Leopard/Snow Leopard from Lion without any disk? My friend has a Mid 2010 Macbook pro with Mac OS X Lion installed on it. She wants to restore it (as in format/erase and get a fresh start). However she does not have any disks. 

When trying to restore using the CMD+R option during the boot process she is asked to sign in with her account but then a message saying she does not have OS X Lion purchased under her account prevents her from continuing with the installation. Is there a way to buy this online so she can proceed?

Also, she has the Recovery Partition in her HD so going back to Leopard/Snow Leopard is also an option. Is it possible? How?

Any hints on how to proceed without having to get an actual physical media is appreciated.

Thanks
There are two possible solutions from my limited knowledge:
First method
Install the OS X Recovery Disc Assistant on a USB drive and reinstall Lion.
From the OS X Recovery Disc Assistant guide:

To create an external OS X Recovery, download the OS X Recovery Disk Assistant application. Insert an external drive, launch the OS X  Recovery Disk Assistant,  select the drive where you would like to install, and follow the on screen instructions.
When the OS X Recovery Disk Assistant completes, the new partition will not be visible in the Finder or Disk Utility. To access OS X Recovery, reboot the computer while holding the Option key. Select Recovery HD from the Startup Manager.

If her Recovery partition won't let you install already, I'm guessing there's a chance this might fail, but it's a least free to test and see.
Second method
Buy OSX Lion from Apple.
OS X Lion is still sold by Apple, so you could just buy a new disc and install using it.