I'd like to introduce my 10 year old daughter to Trap Shooting. She is small in stature. Thankfully I have a Stoeger Condor with interchangeable barrels in 12 and 20 gauge. In terms of minimizing recoil which way would be easier? If I do go the route of the 12 Gauge, is there a particular low recoil shell on the market that will not break the bank?
I am not sure what is available on the market, but a 7/8 or 1 oz. load is pretty mild. I loaded a lot of 1 oz. loads for my daughter and later switched to it for 16 yd. targets myself. The 7/8 oz. I used for skeet. They were definitely a "powder puff" load with very low recoil. I am sure if you check around you may be able to find a low recoil load, but that doesn't mean they will be low priced. Have you considered getting into loading your own? You could customize the loads to her liking.
The weight of the gun will be a big factor in recoil. The heavier the gun, the lesser the felt recoil.
Also, keep in mind the speed of the shells you are looking at. You need to get the slowest speed you can find in the desired weight shot. I would probably try to be around 1100 fps.
The 7/8 oz load will be better than 1 oz, again for recoil.
Gun fit is most important followed by weight.I bought my son two Franchi affinity compacts,one in 20ga and one in 12ga.I had good grind to fit kick eez pads put on each because the stock recoil pads were too thin.We fitted and shimmed both guns exactly the same so they fit him perfect.I bought the 12ga primarily for trap but he shoots the 20ga much better because it's quite a bit lighter.It's not the recoil either because he shoots trap with high brass 20ga and hunts with 3" mags with no problem.We've gone through thousands and thousands of rifle and shotgun loads since he was 6 years old.My son can shoot very well for a kid his age and I attribute much of it to using very light rifles and shotguns.