If you don't have many FB friends then it really isn't the place to promote something.
Don't know what it is you need to promote, but do you have actual friends who have more friends on Facebook who might be able to promote for you? It's generally pretty tricky to advertise anything on the Internet unless you have strong social media connections.
You can link a business/interest page to your existing page, and flip between the 2, but given your work frown upon this, it would probably be better to use a 'spare' email address or your DH to set up an account.
Difficult to answer based on the info you've given. In all honesty I'd set up another account, then you can be certain there are no links to your profession. The only think making me pause is that you used the word 'promote' which makes me think you want to make something as visible to a wide an audience as possible. Therefore a new FB account may not be the best as you would not have many friends who would see what you are promoting iyswim
I (as an adult) need to promote something for DD; it has been suggested that I do this on Facebook
I have a limited knowledge of Facebook, have an account I barely use & have a few bits about my work on there. My profession prefers us not to use Facebook for any reason/connection with the business.
So do I set up another Facebook account purely to promote DD (using a spare email address) or do I use DH (who has never had a Facebook account) & set up a page in his name or use my account (& remove all references to my work - and if I do that do they really all get properly deleted) or something different (& probably very clever)?