I'd get a 1100 in 20 ga. Going on what you said she 'might' be shooting, IMHO that makes the most sense. A good 20 ga shooter can do almost anything a 12 ga shooter can do. Might be a little light on passing geese, but if you decoying them, a 20 would be fine. On the plus side, she doesn't have to 'shuck' each round and it'll have alittle reduced recoil.