After a decade of fighting in the courts in a failed attempt to regain a lost empire, the Quinn family’s bet on online gambling is starting to pay off.  QuinnBet is part-owned by Brenda Quinn, the youngest daughter of Sean Quinn, while the remaining shares are held in trust for his grandchildren. The betting business says it expects to report an after-tax profit of €1.5 million in 2020 and a sharp increase in revenues. The chief executive of the business is Stephen Kelly, a son-in-law of Sean Quinn, and the company also employs Sean Quinn’s son Sean Quinn Jr and…