Can anyone advise on the number of times someone should call if unable to contact her.
Or the number of times someone should call if unable to contact her while leaving a message
that it is ok to return a call and leave a message before the calls becomes unwelcomed or she's not interested?
In the case of civlians, I call one time only.  If no return call, I move on.  I figure she's not interested.
However, these are special circumstances.
Thanks in advance

They will often state if they are on vacation or otherwise out of touch.

Generally, I will wait 2-3 days, then contact once more, and if still nothing I'll make other plans.

Email I think works best for initial contact, and some Providers specify (assuming this is an initial contact).  If you only have a phone contact, and you've already left a message, and haven't heard a response, then move on.  Unless this is the one you MUST see, then wait a few days and try one more time.  I think anything more than 2x and she isn't responding means she isn't available or she's not interested.

Since the holidays, many Providers are with their families or on hiatus.  I would check the Regional Boards to find out who is in town during the holiday weekend, or see if any of your other "favorites" show they will be in during the holidays on their calendars.