Eileen, where are you located?
A good source of information is often your state's disability services organizations. I'm near Raleigh, NC, and several years ago attended a couple conference sessions for disability issues, pointed directly at hearing assistance esp. for churches. Very instructive.
Fun fact: Hearing loss and the attendant separation of the sufferer from interaction with their worship service is a major reason older people leave churches as their hearing deteriorates. They get frustrated at not being 'up to speed' on things, at not being able to follow worship services, conversational flow, etc. So, doing work for helping your hard-of-hearing members is a mizpah.
In NC, it's
https://www.ncdhhs.gov/assistance/hearing-loss/deaf-servicesFWIW, I help sound at my church, and about 8 years ago a member family donated a hearing assistance system (think it's a Williams Sound VP-37; transmitter & receivers are switchable for frequency) and several of the receivers. We just feed a separate mix-bus off our board to the transmitter. We have a Midas M32R console, and can nicely tailor that feed in a separate mix-bus, similar to our floor monitors;
Good luck!