Much of the time it took for life to form was because the planet was still forming. It was highly volcanically active and was being constantly bombarded with cosmic debris as it was clearing its orbital path. All of that would be a significant hindrance to complex life evolving. As the planet settled and orbital impacts waned then life evolved.

But consider that the moons of Jupiter and Saturn are already formed and have been for some time, and have already cleared their orbital paths. I would imagine the time to evolve life would be much shorter than it was for us. Especially if the time between now in then is full of us sending probes and robots that are contaminated with earths biological materials. All they need is the right conditions.