Presumably born on Asgard her parent were killed by a plague. She and her twin sister were saved by a Batarian who came cross them when he escaped the mercenaries. He picked him up and brought the two girls up. When they were in their teen years he started to use them for his dirty work. Ria escaped when she was sent onto a mission to get the ship. Leaving her twin sister Tia A'reena on Asgard. Ria first planet to visit was strangely Citadel. She got there after being exhausted and drifting in space. She immediately fell in love with the place and promised to return here as soon as she could. Because not having any documents about who she is she was hunted. The C-Sec hunted her a lot, but using her skills she was able to learn about citadel better when any other inhabitant except of keepers.
She was hunted nearly for a year till a male Turian was able to hunt her down. She was pursued till she was in the corner. The turian was ambitious and loyal. She was placed in the corner where she had no escape and her abilities were to tired to be used. The turian was about to make a shot when he suddenly felt that it was wrong. She never had documents and she was too young. He felt sorry for her and released her. After it she was able to construct a profile and start some sort of an ID card which the turian helped her to construct. As the time progressed the turian became her best friend and the two hanged out together. She was 40 by the time she started to work in Asari Embassy. SHe was very well respected. In the free time her best friend learned her to fight.
As the time progressed this C-Sec officer became C-Sec executor. The relation continued as friendship but when the council witnessed Ria they took her to work as one of important workers in the Citadel Tower. The current executor went her to celebrate it. She quickly allowed him home where things took another spin. Her long term friendship developed into love and the two lived together for quite some bit. When the family of turian was killed in a space crash the turian write new contract which said that all his property would be given to her. She never knew about.
The turian made a lot of enemies and one was a Spectre. He hated him for once not doing as he said. The turian was also old. He couldn't give anything to Ria who because of her age was quite young in asari terms. The turian was working in his office after a disagreement with Ria. He returned to his and started to work and the spectre rushed into the room and killed everyone. He dumped there bodies into the river. Ria learned about after getting a high some of money from what the turian left her.
She tracked the spectre and killed him. With cold blood. At first she threw him out of his house and when shot 34 times. She took his belongings and doubled her cash. After it she asked to be fired from the council because of personnel matters. She ventured into the galaxy. She started to become richer and richer waiting nearly a hundred before the return to Citadel. At this point she was very wealthy and everyone knew he for different reasons. The council promotes her higher up and she become official advisor to entire council. At this time she meets with other powerful biotic and starts a operation known as Biotic Coalition to help make biotics life easier.
As the In humanity is found she advises caution because they are unknown but surprisingly in the first days of their life on citadel fells in love with one.
Later when the Inquisitor war broke out she tried to use any means necessary to help Citadel Alliance. She also travels to Omega where she is injured but is saved by her sister who replies that she only expects to get payed well for it. She and her sister start to come down but when the Thessia rebellions broke out she and her sister were on different camps again.