She has an impressive knowledge of Physics, which even Sheldon acknowledges and helps him to reconcile the "black hole information paradox" with his "theory of string network condensates" leading to a theorem that would be paradigm altering.
He also likes her humour and initially is rather happy about her company. She prepares his food, reviews his research and even pedicures his feet.
However, she does not think that any non-scientific activities, such as Halo Night, Paintball, reading comic books or watching Battlestar Galactica are appropriate for a mind as great as Sheldon's and pushes him into working only and neglecting his friends and all other activities. Sheldon realises that he feels uncomfortable with this dominance and rather unsuccessfully tries to get rid of her. Eventually she leaves him when he refuses to share credit with her by naming the theorem after both of them (0206).
Ramona: He's a gift to the whole world and we can't be selfish.
She is played by Riki Lindhome.