Try buying some .38 Special Wadcutter target loads. These are usually ~148 grains traveling in the vicinity of 700-750 fps. They are very mild, not very loud, and extremely accurate in many revolvers. When I want work on accuracy, trigger control, flinch, etc., I reach for these. When introducing a new shooter to revolvers, I use these.
Light weight bullets in minimal powder loads would be the best for recoil-sensitive shooters. A better suggestion might be to buy several loads and weighted bullets and let her tell you which load she feels comfortable with -- you might be surprised as to what she considers best for her....Good Luck