I've had good luck with Gorilla glue. Sumo glue is a similar polyurethane glue that is more white. Mix either with a couple drops of elmer's white glue (or water-moisture makes it "kick"). Do a small batch first to get a feel for it-it foams up.
The cub is pretty tough but it (like most planes) has a bunch of known weaknesses; battery box, wing struts, tail, propeller breakage (any plane with a puller prop in a new flier's hands), servo mount glue, wheels too small for grass, etc.
For a group of people that just discuss the Cub go here:
For a bunch of suggestions on repair and improvements go here:
For a long thread about the Cub go here:
And there's probably a thread in this forum if you search. All are worth reading.
I've had my Cub about a month, probably got 40 flights on it (more on an Aerobird Challenger). If I had a new one I would do almost ALL of the improvements before I flew it to help prevent as much damage with the inevitable crash.
Strongly suggest a prop saver, switch over to an E-flite 1080 or GWS HD 1060 prop (cheaper, better) and since you'll have the battery box out do the various gluing and reinforcing that is suggested. Gluing in a carbon or bamboo spar/reinforcement in the skinny tail is a good idea. Almost everyone breaks that off in a landing cartwheel. Larger wheels make take off and landing easier.
BTW-15 mph is a goodly amount of wind for the Cub. Landing gets pretty dicey for me over 8-10. Last time I did that I was doing fine until the last landing created a cartwheel and I broke off the tail (also a good way to break gears in the servo and mess up the tail feathers. That's when I added my carbon reinforcement.