Ditto the above 2 responses. Kittens do not understand being spanked. The only thing that will do is make her scared, and she may eventually fight back. Since she's on her own, she didn't learn proper play behavior from her siblings. Kittens ALWAYS play rough and bite one another, but they learn not to bite from their siblings (who will hiss, growl, and walk away). Since she doesn't have her siblings, she needs to learn that from you. When she bites, just say "NO" loud enough to get her attention, and walk away, and give her a toy to play rough with. Eventually she will learn that when she bites, she doesn't get your attention.