Sounds to me like fishing and the wilderness camping experience are your primary goals.

If that's true then I think you are getting too ambitious trying to get to Jesse via Beaverhouse or Sue Falls.

Since this is a first trip, the objective should be to leave 'em wanting more and not push them too hard.  

Most 13-year-olds are not nearly as goal-oriented as adults.  They just want to have fun fishing, swimming, throwing rocks, exploring around camp, chasing crawdads, helping cook, finding wood, making fire, or whatever else catches their attention for the moment.

I took my 12-year-old daughter up last year with a friend and her dad and we nearly pushed them too hard just going from Bottle portage up into McAree and Minn with a Black Robe exit on a 5-day trip.  They had the most fun once we hit our base camp on Minn and they didn't have to paddle too much each day or set-up/break-down camp.

If  I were you I'd enter Beaverhouse and stay on Quetico and/or Cirrus.  There's plenty of good fishing in those lakes and some pretty nice campsites too.  Portaging would be minimal.  You could stay out of the wind as needed if you use care in campsite selection.  You could also introduce them to the history of the park by showing them the pictographs on Quetico Lake.  If they feel adventurous, take a daytrip to whichever of the two lakes you don't stay on.

The next best alternative is a Sue Falls entry.  They'll definitely get a good taste of portaging if that's what you want.  Most of them are easy but the Sue Falls portage will challenge them a bit.  Sue Falls itself is a fun place for a kid to explore and again the fishing around there is very good.  A daytrip to Soho Lake would be possible and you'll find some good bass/walleye fishing on the east end of Soho.

You've got the right idea to try to get them on some fast fishing.  just carry that idea through to the rest of the trip.  Easy and fun is what you want.  You'll know you've accomplished your goal if they are eagerly talking about "next time" on the way home.