First of all, we need to keep in mind that the female pelvis differs from the male's one. The female pelvis bones are lighter and less dense, wider, the pubic arch is wider, and many more characteristic, thus, the female is more flexible and has a natural mobility for the squat, meaning, a better development for the glutes. The best strategy for reshaping the backside is to perform the right exercises. Many women think that lifting a light weight for multiple reps is the best way to define their muscles, however it's an incorrect assumption. You will get better results pushing your body hard and lifting as heavy as your capacity allow you to, so that's the prime focus here.
Of-course, squats are known internationally by their effectiveness, but most women short themselves on this exercise, going only part-way down through the motion won't fully recruit the glutes muscles, unless you have some former injuries, knee pain, or back pain, there is no reason to not push yourself and squat to the dept.
2. SPLIT SQUATS
3 SETS / 10 REPS
This exercise will place a large amount of stress on a single leg right near the bum region so you can see quick results and improvements in strength. You can perform this exercise with either a barbell or dumbbells, also it will target your core, as the abs help maintain your balance. More the steps are lengthen, more emphasis on the hamstrings rather than the quads, which is the goal of this exercise.
3. JUMP SQUATS or BOX JUMPS
4 SETS / 10-15 JUMPS
Finally this exercise is a finisher for your glutes workout, it will target the entire lower body, glutes, quads, and hamstrings, it is also a cardio exercise for burning calories. The higher the jump is being performed during this exercise the more you'll be targeting the glutes, so each time try to push yourself and get a higher box each time you perform this exercise.