Watertown is way north of the SR.I hope you have studs for your boots as they are a must on that river.My go to tackle shop up there is All Seasons,it's right across the street from Fat Nancy.The flies you use in Erie will work,but get some BH pheasant tail and prince nympth's size 10,muddler minnows in black,olive and green size 10.Use flora tippet 8-10 wt.Go to the LFZ and park at the church ,cross the street and fish off the rocks,that would be the best place for your wife to catch one and you won't need to wade.I think a season non resident license is $50.