Everything that is said above, yes, I'd ask, and did ask when I interviewed MWs.
Also, I'd add, what newborn complications she has had to deal with.
How she feels about delaying cord clamping
How much help will she be with Breastfeeding
Her protocol on opting out of Rhogam prenatally, and other prenatal testing
How her births have gone with her kids
Most importantly, how much she knows about fetal positioning. Not just breech vs. head down, but also anterior vs. posterior, how to turn a baby in labor and different positions, how to recognize a baby that is turned funny and stalling labor and how to help rotate him. Fetal positioning has a lot to do with how a birth goes. You can have a great pelvis, small baby, and strong contractions, but if the baby is asynclitic, then it can cause what would be a quick labor to be very prolonged, and recognizing this early can mean a lot when it comes to maternal exhaustion.