I think she's already asked the question.
She's asking who to ask about what to ask for her Cally, as she wants to sell it

Not sure what the going rate for a Diamond black M reg 8v is, but final price depends on mileage, condition, modifications (eg aftermarket alloys etc), history, does it have MOT and tax etc.
Assuming its a decent car, with average mileage, taxed and with a longish MOT, i'd say ball park figure of £700ish?