Welcome to the all new and improve Aria Jackson!!! Her backstory is long
But technically she was made to be stronger than both Laura and Logan. Although originally she had three claws on each hand she was experimented on, which to her surprise when she woke up, one hand had two claws. Thinking that they stole one of them she tried to come after them only after finding out they put it in her foot. Making her more dangerous.
She turned out to be a normal fighter just like Logan and Laura.
So to them she was a failed experiment whom they wanted to kill but they never were able to.