It's often the case when an expectant Mum is wanting to fall into labour that a good dose of "letting go" will help her relax enough to naturally start the birthing process.
This could be a bath, a meditation of "just being" a massage or some acupuncture. These things switch off the tension and excitement so that the body and baby can do their thing.
It sounds simple but it's so worth a try.
Best, Tabitha