Females (and males too) may sleep with a pillow in between their legs for several reasons, including.
1. Alignment.
Placing a pillow between the legs can help align the hips and reduce strain on the lower back and pelvis, which can be particularly beneficial for pregnant women or those with lower back pain.
2. Comfort.
For some people, sleeping with a pillow between the legs simply feels more comfortable and helps them relax, especially if they are side sleepers.
3. Temperature regulation.
In some cases, placing a pillow between the legs can help regulate body temperature by providing a barrier between the legs, which can be helpful in hot or humid environments.
4. Joint support.
The pillow can provide support to the knees and ankles, which can be especially beneficial for those with joint pain or arthritis.
sleeping with a pillow between the legs is a personal preference, but it can have several potential benefits for comfort and support during sleep.