I'd put it at like a 7. It seems overly personal to me somehow, maybe because giving somebody flowers can have romantic connotations. I would be more likely to tell my therapist about the urge to buy flowers, rather than actually surprising her with some. But then I don't have a lot of gift-givey urges toward her in general, so I don't know. I would likely feel differently if they were flowers you had grown yourself (putting that at like a 3).