A.
Well unfortunately I have not had the pleasure of treating Cheryl. She does have quite a bright shade however so I would guess she is possibly a B1 or B0.

For you, I would recommend having a consultation with a dentist to help you pick a shade that will give you the result you are looking for. Simply selecting the same shade as Cheryl may not give you the same result due to differences in complexion, shape of teeth and many other factors.