In what way were they on iCloud?
If it was Photo Stream, then it's not recoverable. Photo Stream was only meant as a convenient way to copy photos from one device or computer to another. It wasn't permanent. Old photos won't re-synced to a device, only ones taken after the feature was turned on. {this is changing under iOS 8, though it's unclear exactly how}
If she was keeping them in the Camera Roll and doing iCloud backups, they should recover when she restores the iPad from the backup. Provided Photos wasn't turned off. It's on by default.
If the were being placed in Shared Photo Stream albums, she will need to turn on the feature in Settings > Photos; at which point they will show up in the Shared tab in the Photos album.
These are the only ways, that I know of, that photos exist in iCloud. At least with native apps.
It is possible for a third party app to store photos in iCloud. To get those back you would have to install that app again, and maybe sign in with whatever account you used with that app.
