Can a ford edge fit 3 car seats?

It depends on what model of the Ford Edge You're looking at, but neither the 2019 nor the 2020 can safely fit three car seats; it's limited to two seats, of one of latch, rear-facing convertible, forward-facing convertible, infant or booster. You could potentially kludge something, but You'd be putting the safety of Your children at risk, which isn't something any sane person would recommend --- and nor would I. For some roomier vehicles which can better accommodate Your large brood, check out the 2020 Subaru Ascent, the Chrysler Pacifica, or maybe the Toyota Avalon, all of which can more safely allow A3seat configuration.