the family history is they originated from minneapolis, mn but the family moved to boston after their mom died in a car accident. that was 24 years ago if i'm doing my math right. their dad remains an active and involved parent. still, bea felt she had to step in and help out as the oldest among her siblings. ~snowowl lists him at 34 (possibly negotiable?) so there's only a 6-year gap between the brother and bea. that could've resulted in animosity if he felt he was being coddled when he'd rather be treated as an equal. up to you! bea will be a proud busybody in her brother's life regardless of his personality type.
some possible faces that spring to mind are brenton thwaites, taron egerton, chris wood, jai courtney, sam clafin, scott eastwood, kit harrington, matthew daddario? i'm super not picky and a strong family resemblance isn't a big deal imo. lord knows i look nothing like my siblings.