She can happily afford the maintainence on her Gladius and really why the hell would that matter to you? She doesn't want to throw money away when she doesn't have to.
I really take exception with the elitist attitude that is implied in your quote above.. people don't have to be have a certain income bracket to ride and maybe, just maybe they don't enjoy getting hosed down by people that think they have to spend X amount of dollars to enjoy a sport.
In your first post I would point out that it is important to seperate out reliability (repair) costs from maintenace costs. They are two different things. Not knowing which is which it hard to comment on. BMW has typically had a 3 year warranty so if buying new repair shouldn't be an issue for at least that long. Of course not having a problem is even better.
Its not elitist, its reality. Motorcycles cost money to run. Tires for example do not last a long time and they are expensive compared to say cars. The Gear we use, helmets, jackets, gloves, cost money, more than they should in my opinion, but they do because they are specialized to our hobby. In fact you do need to have a certain income level to ride just as you do for anything else. It can certainly vary from the guy who has a mid 80s rat bike to the guy who has a K1600 BMW but its stone reality.
So the reason why the hell it matters to me are two fold; your original post made it sound like cost is a big object although it was not clear why. You have now clarified that its because she simply doesn't want to pay what she perceives as too high a cost for the bike involved. Fine.
Two, is that I see a lot of people come into this hobby and then complain about the costs of it when its clear that it simply isn't affordable for them. If thats not her issue, fine, it is for a lot of people and those most commonly taken by surprise are those new to the hobby and were simply not aware of what it can cost. Or as my wife would put it "they should just give you the bike and make it up on parts and accessories".
Certainly there are ways to trim costs in some areas and what they do with their money is their business but I see it as pointing out a reality. I've been doing this for over 40 years and have a pretty good idea of the varying costs involved and think its worth pointing out. I have seen it with all levels of bikes, I used to own a GL1800 and would constantly see people bitch about the costs of this and that. Well, lets see, I spent in excess of $20k for this bike and now I can't afford this or that farkle, tires or maintenance. Seems a little strange to me. If thats elitist to you well, sorry.
So, to answer your original question, if the BMW that fits well is off the table to her then you're pretty much stuck with modifying something else. The VStrom is probably the closest thing to that bike I know of although Suzuki did at one time make a factory lowering kit for the DR650 and as far as I know still doesn. I had one, its a good bike, not as good a street bike as a Strom but defintely a better dirt bike. Tank is really too small, seat is an abomination to mankind.
A Strom can probably easily be lowered an inch by tinkering with the seat and sliding the fork tubes up, either a shorter shock or some type of linkage lowering kit. Probably also need to change the sidestand. I don't like doing stuff like that because I feel it gets into geometry changes which I feel are things I like to be factory tested. That said, people do it all the time.
For the rear end lowering you might google Norm Kouba, he makes a variety of links for different bikes, one purpose being lowering.
As for the current bike she might also try something simple like a taller boot or having a boot maker add some height to existing boots if possible.