Well Mordred's existence while she was alive was pretty much one of pure manipulation and tragedy, she spent her entire life just being used as a puppet and tool by Morgan.
She was created by Morgan for the sole purpose of killing Arturia and as a result her 'upbringing' was just brainwashing and manipulation to try and get her to despise Arturia and infiltrate Camelot, with Morgan convincing Mordred that she was the rightful king of Britain and that Arturia had taken it from her.
When Mordred did eventually infiltrate Camelot, she instead became infatuated with Arturia, adoring and admiring her as the perfect king, giving up her goals of overthrowing her.
To break Mordred's admiration, Morgan manipulated her by purposely revealing that she was Arturia's child, knowing that Mordred would go to Arturia with this information and get rejected.
After being rejected as Morgan predicted Mordred began to despise Arturia and rebelled against her, which lead to them both killing one another at Camlann.
Also, due to Mordred being created artificially as a homunculus, her growth rate was increased, meaning her life was only around 8 years long. Being a homunculus also caused Mordred to hate normal humans somewhat, being jealous of their natural existence and lifespans.
Mordred only really wanted to be accepted and recognised by Arturia, to prove herself worthy, but instead was manipulated into rebelling against her own father and dying in the process. Even centuries later her one wish is to prove herself to Arturia, a wish she tried to fulfill during the holy grail war, but was unable to due to her Master's death.