You can share your collections in the Adobe Cloud from Lightroom Classic, which gives you complete control over who gets to see the images and who doesn't. There are plenty of tutorials on YouTube and adobe.com. Once you have synced a collection with the cloud, you can send invitations to people you want to allow to see the images. Keywords will be there, titles will be there, I believe they can add comments (but I never tried). However, downloading a higher resolution copy won't happen, as the images in the cloud are maximum of about 2500 pixels on the long side. Still, it's an easy solution, the people viewing can view it on a computer or on a mobile device.
If you really have to have the high-res images available for download, Flickr (and probably other services) allow you to upload the full resolution image and control who sees it, but there's more work, and the free Flickr limits you to (I think) 1000 images.
Easy: Create a Collection and drag all of the images to that Collection. YOu can have more than one and also images can be in more than one collection. (That means that if you have a photo of Aunt Maude, and she's from family X and she shows up in a photo of family Y, that photo can be in both collections.
Anyhow, set up that collection to Sync to the Clouds: This can be accessed by you in your phone, tablet, whatever. It can also be accessed in Lightroom.Adobe.com.
When you go to that site, you can share openly or privately to others. If you copy the Collection's link and send that to family ONLY they can access that Collection. If you need more information, let me know and I'll go into more detail.
I do suggest you first start with a few images to make sure you have the process down correctly than expand as needed.
However, those images in those shared collections are smart previews. They are big enough to be downloaded and printed 4 x 6" or maybe 5 x 7", but if the recipient wants substantial enlargements those previews probably wouldn't hold up. Otherwise your suggestion is quite workable.
" Want the Lightroom keywords to show up somehow and somewhere
Wants the keywords to be visible (and the title) if possible when the family members look at the photos"
Shared albums no longer display keywords. A change was made in one of the LR ecosystem updates that added capability to edit keywords in the Web app. Unfortunately, that update also eliminated ability to see keywords in shared collections. The Title and Caption fields are visible along with the City, State, and Country fields. I haven't tested it exhaustively so there may be other fields visible in shared albums, but the lack of keywords in shared albums is a showstopper for most of my usage.