This may offend some in these days of political correctness above all else, but there are some very fundamental physical differences between men and women. The male body shape generally includes narrower hips and wider shoulders, while the female body shape tends toward wider hips with narrower torso and shoulders.
Holster design in general has focused primarily on the male form, for which a higher ride and forward cant assists in concealing the holstered handgun profile when carried just behind the strong-side hip. When females use holsters of this general design the result frequently includes general discomfort and difficulties in accessing the firearm readily. The grip-frame of the handgun can jab into the ribcage, on or near the brassiere line, causing the user to move the holstered handgun forward to a position that requires contortion of the hand, wrist, elbow, and shoulder to draw the handgun.
Many ladies will be better served with a holster having a neutral cant (which typically lowers ride height somewhat) worn directly over the strong-side hip (3:00 position for a right-hand shooter), or just a bit forward of the hip.
The belts usually offered for ladies are seldom of a type or design capable of supporting the weight and anchoring the holster in position. Narrow belts in general, and belts of flexible or flimsy materials will not provide the foundation required for the holstered handgun. A solidly constructed belt of 1.25" to 1.5" width is recommended to support the weight and anchor the holster firmly without having to be tightened to an uncomfortable degree in order to serve the purpose.
Cover garments will require some consideration. Form-fitting tops will not do as well as loose-fitting blouses, shirts, sweaters, etc. Soft woven fabrics will not conceal as well as those having some substance and body (broadcloth, denim, or similar).
Fortunately, most ladies seem to grasp the concept of accessorizing better than many men, and won't have much difficulty with the idea of dressing around the gun. Making wardrobe changes and shopping seem to be easier for the ladies than some of us guys.
Beyond these points, we need to look at the handgun itself. The S&W Shield is a compact design with polymer frame, semi-auto pistol with magazine in the grip-frame. These features result in a balance point of the weight (including ammunition load) at or near the rear of the trigger guard area. That balance point needs to be on the belt-line, otherwise the holstered handgun can have a tendency to tip out away from the body which compromises both concealment and security. With the compact semi-autos this can result in some challenges to accessibility, as the grip-frame may be very close to the belt-line and some holster designs may not allow sufficient space to obtain a solid grip during the draw. I would suggest keeping these thoughts in mind while looking at different holster designs.