Can I do this?

Anything is possible if you dedicate yourself to the training and listen to your body. 

Just follow the schedule, try not to skip any runs, rest when you need it, and go for it!

Hmm.  I guess I get to be the voice of dissent. 

Point 1.  I am absolutely certain that you could complete a marathon (and probably do relatively well) given your current mileage of 10-15 per week.  

Point 2.  I'm not stalking you, but I recall from your post a week or so ago about your first Oly that you are relatively young, and female.  

Point 3.  Because you are young and female, running the amount of miles to be sufficiently prepared for a stand alone marathon (max of 35/wk in your plan) presents certain health risks that a young man or older female would not experience. 

I'm specifically thinking of female athlete triad, which, in a nutshell, is disordered eating, reduced bone density, and amenorrhea.  There is a fair amount of debate in the running community about what sort of mileage for a young female is too much, too soon.  By putting in 35 mile weeks, you are very near that threshold. 

I would encourage you to look at your reasons for doing a marathon.  It might be better for your running in the long term to forgo the marathon until you're out of college, and work on speed between now and then. 

I think you can do it just fine if you commit to the training. You have more than enough time to have a good base without overdoing it, and can move right into one of the 18 week programs you shared (I use one of those, btw, and it has always worked well). With your volume of swimming, you'll most definitely have to make some compromises in your schedule and it might be that your cycling suffers a bit, but you can always pick it back up after the spring mary.

On the young female front, I was 25 when I did my first marathon and while it's definitely easier for me to do now in my 30s, I didn't find there to be any health challenges at that age. Good luck and have fun with it, it's a great experience!

I disagree.... 10 - 15 miles/week is not nearly enough to think of running a marathon.  As OP stated in her post 20 miles/week is a good STARTING point for a marathon training plan.

again I disagree... unless you are still in high school ie. under 18 you should have no health problems if you train smart.  disordered eating, reduced bone density and amenorrhea in a young adult female  is not caused by a reasonable low mileage plan that builds progressively. (35 miles/week is low mileage for a marathon training plan) .... where did you get this info?

I think the OP might actually still be in high school - OP, how old are you?

Edit: The OP has a video on her profile - she's in high school.

I'm not a marathoner AT ALL, in fact, I'm training for my first right now, but my only thought would be that having meets every other weekend would conflict too much with the long runs. Unless, you put your long runs in the middle of the week. And as the plan progresses, the mid-week runs are going to get longer. Otherwise, you wouldn't want to run, say 13 miles the day before a meet (then you're fatigued for the meet) or the day after (fatigued from the meet and therefore might have a crappy run). I'm following a marathon plan now (Hal Higdon's Novice) that I've incorporated into my tri training, but I only have one race that conflicts with a "really" long run, so I will do some schedule swapping just for that week. After that triathlon is done, I'm not doing anymore for the year. That would be my concern - being too worn out from all the swimming to be rested enough to perform well during running workouts and not get injured. My sister swam competitively for many, many years, so I know what the schedule is like for them.

Cathyd, you're right in observing that she would have difficulty completing a marathon right now on her current mileage. I meant she would be able to do a marathon with relative ease after her proposed 7 month training program.

In response to your statement that eating right is all you need to prevent female athlete triad, I also believe you are right. I will offer, however, that this is much easier said than done. While it is possible to keep a young female athlete healthy, it takes, at the very least, a knowledgeable coach who really knows what they are doing.

For young female endurance athletes, the cards are stacked against us to stay healthy. The media says that skinny is beautiful. Coaches and casual observers say that skinny is fast (Paula Radcliffe, anyone?) Your peers give you funny looks when you go out for dinner and order a plate of pasta instead of the socially-approved salad with light dressing.

So, we can use Paula Radcliffe as an example maybe. She recently had a child (aka all female systems are go), and is now back to racing. Unfortunately, the casual high school athlete does not have access to the same coaching / dietary resources that elites do, and its hard to get it right.

Here are a couple of links I dug up about the female athlete triad. They are both from the American College of Sports Medicine.

female athlete health challenges prevalent but misunderstood

http://www.acsm.org/AM/Template.cfm?Section=Search&template=/CM/HTMLDisplay.cfm&ContentID=5355

Female athlete triad: education is key

http://www.acsm.org/AM/Template.cfm?Section=Search&section=20024&template=/CM/ContentDisplay.cfm&ContentFileID=704