User blog comment:ArthurMerlinLancelot/"He is your destiny, and he is your doom"/@comment-4892425-20121225112528/@comment-5910979-20121226093701

Morgana had little choice if any. She had a guardian/father who hated and despised magic and for all she could assume, he would've executed her on the spot if he found out. Then to have her most trusted friend at the time (Merlin) betray and try to kill her would make anyone cold, hateful and distrustful to him and anyone else she might've called friend. With Merlin turning his back on her,  she had no one to turn to then except Morgause. Her original goal wasn't to take the throne, but to get rid of Uther. It wasn't until after she learned another deeper betrayal (the lie of her parentage), and with Morgause's persuasion did she want the throne because it would've given her a better position to return magic.