Every story needs a protaganist. It might not be as serious a problem as you think.
If you really don't feel comfortable with it, maybe talk to the GM about other possible characters, maybe Lora has gone missing, and you can play her fiancee or boyfriend who is setting off to look for her? If you pitched that to me. I'd roll with it.
Then I'd make Lora the apprentice of her father, and give you guys a second antagonist with a personal connection to everyone. Then your character has some of the limelight, but so do the other characters.
A simple solution, is to have neither one of them know who the other one is. I.e. the Vader/Luke scenario minus Bespin.
You could also make her fairly inept, and though she is on a quest for vengeance, the fact is she needs the rest of the party to succeed, but that sounds less appealing to me than the limelight.
I think going the way you are is fine, just keep an eye out for twists you could make to the original Luke/Vader story. The child/parent conflict is a classic for a reason
"Wit is educated insolence." - Aristotle