@indigomoth - I do think that there has to come a point where an aspiring actor or actress needs to realize that it might not happen for them. It's an incredibly tough industry because there are so many people wanting to get into it.
Some of it is simply luck. Whether that is luck of the genetic draw, or the luck of being in the right place at the right time.
And, to be honest, if it is the acting itself that is what calls a person to the job, they can always just act in small, hometown plays. If it's fame and fortune they want, they are better off trying to get it some other way.