Beeper is a good, easy solution. And it has a few platforms that might entice your family (FB, x, Whatsapp, signal, etc). It’s basically matrix with a bunch of bridges preset up… it can be self hosted if you really want to be privacy focused… I like it as it makes the login experience much easier than a traditional matrix app (like it just email them a code each login)
@FenrirIII oooh… i love this and have thought of this in the past… I just assumed it was unreasonable…