My advantage is that I come from a long way away! And the WG who does this is one I totally trust - she's a true professional.
If she was a true professional she wouldn't be asking for your real name!
Its very simple, just don't do it. People have said as firmly as they can repeatedly in this topic you should never do this and you should never need to do this.
Hold your ground. You are the paying customer overall.
Think of it this way. If you had booked an incall and the WG was working from a hotel. If you asked her, what is the name the room is booked under. There is no way she would tell you. So why should it be any different for punters discretion.
Furthermore think of it this further way. The hotel staff are bound by the data protection act. If a random girl phoned up and said, can I confirm is John Smith inside room number 21 tonight.
No hotel worker is going to say "yes" to that as for all they know it could be the guys wife phoning when he was having a secret affair on a fishing expadition and she will come along ready to bludgeon the guy as a result.
The only way the hotel will ever speak to anyone on the phone about a reservation is if it's both the name the booking was made under, and you also confirm the payment details you used to book with (so you'd have to give her your credit card number too). And you do not know that girls name when you book the hotel.
If the hotel doesn't do the above. You could literally report them to the information commissioners office as they are breaching the data protection act.
So don't give out your real name to the working girl. And don't do it ever. People are not saying this because they are paranoid. They are saying this because they are being sensible.