To get to the TTC or Main area, you will have to hop the marathon bus early just like the runners. Regular Disney transportation simply will not get you up there in time.
at a 10 minute pace, there is a possibility of catching her at the TTC then at the DAK. The strategy would be once she passes teh TTC, hop the monorail back to Epcot. It will be too early for a regular Epcot to DAK route so you will want to catch a bus to a resort and from that resort the first bus to DAK. Look to see if the regular buses are running from Epcot - if not, head over to the marathon busses and hop one there. Do not try for a TTC to DAK bus as it will be slower than slow if there is one at that time. Bus traffic into DAK will be fairly quick - out, not so quick. With the new course, spectators have a significant amount of extra time to get to the finish.
Mary always waits for me at the Great Britain runner entrance into the park. From there, she heads up to the finish area and meets me at our spot near the family reunion area. About the time she gets there, I have finished, grabbed food and gear and am just walking up.
One advantage of riding to teh race with your runner is being able to pick out a spot for the reunion. Mary and I find the official area crowded and hard to find one another. We have this special tree that we meet under. It's the second one away from the gate into the reunion area. It was never crowded there until I said something about 4 years ago.