I see both sides of this issue.
Yes, as Savannah said SP's can have a private social life too. There is not a hard and fast rule that an SP can not have a friendship outside of work. Yes, friends can go to functions together. Some may not charge at all, some may want a few bucks to pay a babysitter, etc ...
If you are "hiring someone for the event as your escort" - you will pay for it, 600 to 1000 for a 6 hour dinner date.
Those of us that are single - will not have issue with a beautiful lady on our arm as our date at a work or family function. Attached fellas - that's another issue.
Call and ask - the worse she could say is NO.