Ariel Winter -- Settlement With Mom in the Works

9:14 AM PDT: Based on our sources and conversations at the courthouse, it's becoming clear ... Ariel's sister, Shanelle, will become her guardian and the mother will essentially lose custodial rights.

Sources tell us Ariel Winter and her mother, Chrystal Workman, have worked out a settlement in the "Modern Family" star's guardianship case -- and attorneys for both sides are hammering out details right now ... TMZ has learned.

We're told the lawyers are in the courthouse where a hearing was scheduled to go down today ... possibly to determine if Ariel's mom or her older sister Shanelle Gray would be granted permanent guardianship.

Chrystal is waiting outside the courtroom, and just said loudly ... "They're stripping everything from me."

Shanelle has been Ariel's guardian since allegations surfaced back in October that Chrystal was emotionally and physically abusing Ariel.