Amber Deroras

Amber Lillian Deroras is an antagonist in the series Monsters United. She is Riley's long-lost mother and Gregory's wife. She appears in the Season 4 Finale where Riley, Her sister and Randall makes their trip to the town of Lowell, where her parents have been living since the Science Facility breech in Reeseville 16 years ago.

Backstory
When Amber was in her early 20's, she gave birth to Riley and Carrie, whom were 3 years apart and were dubbed by Amber "The greatest gifts from god". Though not having both for her entire lifetime as babies and toddlers, Amber loved her daughters deeply inside her core and believed that they would have a bright future that would shape and form as they grew older.

Though when their daughters never returned home from camp, they fell depressed as no daughters could replace them in their hearts. Though they had Timmy, their son remained special to them, as losing a third child would ruin their chances of ever showing their offspring's a bright future they wished they could of had with Riley and Carrie.