Where to narrow niche

Hey guys! I am listening to the Entrepreneur trainings where Brooke talks about narrowing a niche and looking for a bit of clarification:

I am a mental health counselor who would like to be able to reach a wider audience via online tools (webinars, trainings, podcasts, etc.) in addition to the one-on-one therapy I do currently. My goal is to still be able to serve individuals who I cannot currently provide therapy to. I did the narrowing your niche worksheet in regards to an online training idea I had and LOVE the results of this. But I guess I am wondering if this niche pertains to my entire business or simply this training. I would like to be able to offer content on a wide range of mental health topics, but I don’t think this would be considered niche work.

For example, Brooke talks about all sorts of coaching topics in her podcast (weight loss, overdrinking, relationships, etc.)….is narrowing the niche more important when considering a particular offering, like a webinar or an online training?

Thanks in advance for the insight!