Blood Is Thicker Than Tears

Two polar opposite siblings, both struck down by tragedy and loneliness. One shys away becoming a lazy and self-conscious loner, the other struggles and achieves beyond her limits.
However the return of a (now grown up) childhood friend, an unexpected love interest, a slew of new friends and accomplices and most importantly his younger siblings unyielding belief will force our protagonist into action. Excuses will no longer be deemed acceptable.