Daily Breeze: Meet the ladies behind the lobster costumes at the Redondo Beach Lobster Festival
Their full-body costumes are hot and they have to be careful not to scare little children, but the five women known as the Lobster Ladies wouldn’t miss the annual Redondo Beach Lobster Festival ...
Meet the ladies behind the lobster costumes at the Redondo Beach Lobster Festival
"Adult children" comes from "adult children of alcoholics", but now has broader reference to adults who were abused emotionally, physically or sexually in childhood.
Merriam-Webster has an entry for half-orphan, meaning someone with only one living parent. They say specifically a child, which would match the usual usage of "orphan" (as mentioned in the question), but it might be used of an adult sometimes, either jocularly or by extension. This doesn't distinguish which parent is dead, but could be combined with a further explanation if it matters.
The best way to do it, I think, would be to forgo the hyphens completely and go with: I am a psychologist who works with children and adults. Anything else is awkward, ambiguous, or both. If it's necessary to emphasize that this individual works with children and adults (i.e., this isn't just introductory information), you could add in a 'both': I am a psychologist who works with both children ...
16 The word adult appear to have derived from the Latin term adultus, meaning grown up, mature, adult, ripe. Adulterate (and its cognate adultery) is reported to derive from the Latin adulterare - to falsify, corrupt. Are the meanings and derivation of adult and adulterate, directly related, or is this just a coincidence of spelling?
"adult children" is sometimes used in contexts where age is important, such as a form requiring someone to list all children under 18 and all adult children living with them. And someone might use it to emphasise that their children have left home or aren't dependent on them. But you wouldn't introduce someone as "my adult child/ren".