Follow the flowchart of rules on "other dependents".  From what you posted it sounds like a yes, but verify each step of the chart.

Last I knew HOH required the person live with taxpayer........He doesn't live with her

Oops, missed the part where they lived apart.  So nope.

"and he lives apart from tax payers main home"

this part confuses me, dont they have to live in the same household?

try IRS interactive assistant

https://www.irs.gov/help/ita

IRS has exceptions for "Relatives who don't have to live with you",  a person related to you in any of the following ways don't have to live with you,  "Your child and many other relatives".

also The Qualifying Relative rules on earning must be below $4,300 does not apply to Disabled.

I thought the exception to not living with you was only allowed for a parent or children of divorced/separated parents..............🤔