Minivan. It's simply the best tool made for the noted job in most (but not all) situations. Arguments for for someone caught up on form over function are going to be highlighting the functions.
Sliding doors are awesome.
Easier ingress/egress to 2nd/3rd row seats in confined parking situations with sliding doors.
Larger access window to 2nd/3rd row seat/cargo area with sliding doors.
No dinging doors when kids get themselves in/out with to sliding doors.
Even more useful with multiple littles than sliding doors...Remote power sliding doors.
Lower floor height makes for easier and more comfortable ingress/egress and loading/unloading.
More accommodating and accessible rear seat space for kids to get themselves in.
More accommodating and accessible rear seat space for one or more adults helping kids get buckled in.
More accommodating and accessible rear seat space for sitting and feeding an infant on the go.
More accommodating and accessible rear seat space for changing a diaper out of the elements while on the go.
More accommodating and accessible rear seat space for having an impromptu picnic.
Large continuous low flat floor space allows toddler and young elementary age dance parties while feeding an infant, changing a diaper, or even just waiting for the other parent to get back from making a quick trip into the store without the kids making it take forever.
Large and accessible enough rear space to quickly get everybody in the rear of the car, including a parent, before buckling everybody up. Standing in the rain not required.
Carries more cargo behind the third row than all CUV's and most SUV's.
Drives better, stops shorter, avoidance maneuvers faster, rides better, parks easier, and gets better fuel economy than any 3 row SUV of similar (or less) interior space.
Does pretty much everything we might use it for, except climb steep snow covered roads and tow, as good or better than a 3 row CUV or SUV.
I'm sure there's more, but it's at least the beginning of a list. As noted, take her to look at both SUV's and minivants, and don't just spend time in the front seats and doing a walk around. Really take your time and spend significant time crawling around and using the all of the rear space/features the way you would have (be able) to day in and day out in real life and then go try to do all of the same things in an SUV.
My wife was dead set against minivans too...Right up until I finally convinced her to actually take a serious look at one. She was almost immediately won over. If she spends some real time around one and still doesn't change her mind, then nothing will. Speaking of which, what really sealed the deal for us was renting one...Even if literally just so that you can experience it in your day to day activities for a weekend or a week, it's probably well worth the cost of knowing.
We went with a lightly used CPO Sedona, and it has been great. The way the 2nd row seats tuck up against the front seats, is considerably faster/easier to use than the Dodge/Chrysler stow-n-go, but cuts into the cargo space in such a way I don't think a 4x8 could be inserted regardless of orientation. Speaking of the stow-n-go seats, the Pacifica's 2nd gen versions are significantly more comfortable for anybody not in a car-seat, in addition to adding a car-seat-safe 2nd row tilting feature for even easier (direct) access to the 3rd row with a car seat secured in the second row. Depending on how you and your wife feel, the Pacifica has a decade newer engineering with improved crash safety and headlight performance over the Caravan.
The Oddy's were nice, but also too new for used and value proposition wasn't there for us new. We did not care for the Sienna. It felt a bit long in the tooth, lacked adaptable 2nd row seating without fully removing the seats, and had a stepped rear floor to accommodate the bulk of the available AWD system.
We really liked the Pacifica, but between being too new for CPO or deep discounting at the time and Chrysler not having figured out why people were having their van completely shut down when making left turns in traffic with no resolution in sight, we had to write it off. But both of those having been resolved, I would be strongly considering one (in addition to Sedona) if I were buying today.