Causes of female lower back pain:

There are many causes of lower back pain in women. Some causes are specific to women, while others are common to all sexes.

Some causes of lower back pain in women include:
Poor posture
Menstrual pain
Endometriosis
Pelvic inflammatory disease
Fibroids
Pregnancy-related back pain
Ovarian cysts
Adenomyosis

Other causes of lower back pain include:
Strained muscle or tendon
Irritated nerve
Fractured lumbar or sacrum bone
Sprains
Herniated disk
Infection of the spine
Kidney or bladder infection
Sleep disorders

Some tips to ease back pain include:
Strengthening core muscles
Stretching daily
Avoiding poor posture
Taking walks
Lifting correctly
Reducing pressure on your back when you sleep
Watching your weight
Quitting smoking