You have really been articulate in explaining your "problem." I could picture it exactly. :)
Well, your girl does seem to have a bad case of clingy-ness...but yes, it is developmental based... and it's separation anxiety as well. NOT anything personal against your Hubby or family members.
Secondly though, there is a thing called "object permanence." That things that "can't" be seen, come back....ie: peek-a-boo games. Try playing these kinds of things with her too. My kids loved playing this from about 7 months old.
I would also try and do some research on the web... see what comes up. My kids weren't that clingy...so I would not know at what things you could try, in your situation.
But I know what you mean about everyone loving your girl...but the "like" part is maybe hot and cold.....because yes, all she does is scream with them and they don't "know" her well enough like you do.
But, yes, babies grow out of it.... and perhaps leave her with your family members for short periods here and there... as a "routine." Kids and babies gets VERY used to "routine." So, my thinking is, if it becomes a "routine" that she stays with your parents or Hubby for certain times of the day, or periods while say you take a bath yourself or while cooking... she MAY get used to this "routine." It may trigger an awareness in her that at certain times you do certain things... that she hangs out with Daddy or Grandma for example. This has happened with my kids...they KNOW that when I am doing certain things... that THEY have "their" routine too. But it has to be consistent.
ALSO, some babies/kids just have certain personalities in which they don't like change, or anything different, and they don't adapt as easy as others. Every temperament is different in a baby.
But yes, they need comfort too... what she is going through is normal.
Sometimes, to switch gears... just try something which will make her laugh! Redirect her. It worked for my kids.
No worries, it is a phase. Although I know it is not easy.
All the best,
Susan