I have Maia for the first time and not sure if I should take it as she uses guns

Yes, works. It stacks with the inherit jumps some ranged weapons, including some guns have (e.g. Fire in the Hole, Kitch Stove, Watershaper's Focus). Meaning that Driving Flight will simply add an additional jump.

It also works with interrupts (e.g. from Concussive Shot and so on) and other effects that might get triggered on hit/crit.

If you have an AoE projectile (e.g. Fire in the Hole) the whole AoE will jump, too. In case of Fire in the Hole you will deal three AoE attacks with one shot (one normal, one jump from Fire in the Hole's "Chain Shot" and one from Driving Flight).

But note that the damage malus for every jump rises per jump. This means every additional jump will deal a bit less damage than the one before (on average).