Struggling with my niche

Hi, I would really like some help with my business niche. I am a certified coach (not life coach school though) and I keep changing my niche. So these are the niche’s that I am considering:

1) Maternity coach – Helping women in corporate jobs get ready for maternity leave and also help them transition back into work.
I have 2 kids and currently pregnant with my third and unofficially I do this in my corporate job.

2) Help mumMs find their purpose and passion again! I feel that we lose this a bit once kids come along and we question life and our passion. I would love to help women find this again.

Are these specific enough? How do you know if you have a good niche that people are willing to pay for and be coached on?

Many thanks