Mariel is nobility... technically. The Lindshaes are a vassal family to a vassal family, with just enough of a hint of royal blood to keep them in the social circles, but not enough to garner any renown, or to cause much intrigue. No, save that for those they serve. Such as the Valmenor.
Mariel knows all about the Valmenor family. It's hard not to, when she's spent more time around them than her actual family. When she was still a young girl, Mariel was sworn to serve the female scion of House Valmenor as handmaiden. Tanelia Valmenor was everything a noble elf ought to be; well-schooled, trained in blade and bow, shrewd and diplomatic at the same time, yet still kind and playful among close company. Though the rules of court kept a certain number of walls between them, Mariel was Tanelia's confidant, playmate, and companion. When Tanelia took it in her head to leave the comforts of the palace to seek adventure and experience in the greater world, it was only natural that Mariel accompany her.
This is how the two of them, a young cleric of Desna and her lady-in-waiting, met the companions. Mariel settled into the role of squire and assistant, and often found herself in a position to council and smooth over strife between the others; weeks in the wilderness can grate on even the best, after all. She never really thought of herself as part of the company - it was Tanelia who had signed the contract, after all, and taken up the quest.
And it was Tanelia who took a bandit's arrow through the eye in their second month on the mission. Just like that, a brigand, barely a man himself, had taken away centuries of life in an instant with little more than a sharp stick. Just that quickly, a woman who had been the center of Mariel's life was removed forever. For days, she was numb with the horror of it, before another realization came to her; She was still alive, and the people around her - her new friends - still needed her help. More now than ever. It was with a sense of obligation and vengeance that Mariel took to the task of clearing the borderlands of hte bandit menace.
Now, the lot of them stand on the verge of nobility in right as well as name. This is a new, strange position for Mariel of House Lindshae. She's been a servant all of her decades of life, living in the shadow of those above her; even if she had the skills, she has no desire to rule. But when asked to serve, to put her "people-skills" to work... well, she couldn't refuse.