Insured, then 11 years old, suffered brain injury and motor disabilities in school bus accident — Representative of insurer felt that it would be benefit for insured to have parent involved in her care — From October 2006 to September 2007 insured's mother took unpaid leave from her full-time employment to look after insured — In September 2007, mother negotiated with her employer to work at 35 percent of her former salary, allowing her to work around insured's appointments — Insurer reimbursed mother for income lost up to fall of 2007 when insured was expected to return to school full time; insurer considered this to be ex gratia payment authorized by s. 206 of Automobile Accident Insurance Act — Insurer notified mother that it would discontinue payment at beginning of school year (decision letter) — Insured appealed to appeal commission seeking payment for difference between mother's salary prior to collision and what she earned at reduced hours — Insurer wrote to mother claiming to withdraw decision letter and made offer to settle on ex gratia basis