Money can be a powerful motivator. A number of the stripper gals and sex worker's I've met go that route to pay for college. College is expensive! Some come back to it later in life, because the 'normal job' just doesn't cut it income wise...
You can work for less than $100 a day in some minimum wage job, or (depending on your looks) make multiples of that at the local strip club (if the club is popular)... it just comes down to whether you are comfortable enough with doing that line of work to go that route.
And a significant number of the sex workers I've met have had husbands that they go home to after their working tours.
As for modeling, that's a tough business to break into. The internet makes it a little easier these days, but D has a lot going against her at this point, if you compare her to the gals you see on say America's Top Model. To begin with, she's not tall...
Sure there are exceptions in the modeling world, but yeah that could go either way. And let's face it, every photographer that has met D mainly just wants to see her naked/exploit her for their own ends! And they don't strike me as being connected to fashion moguls. I'd love to see D 'break the mold' so to speak, but the odds of her succeeding are rather tiny... lots of girls think about becoming models, but so few of them succeed.
A lot of porn talent started out as wanting to be fashion models, only to be 'discovered' by a porn producer. And we have a few examples of gals that do fashion as well as porn. Amia Miley, for example (although she's really cut down on the amount of porn she does these days). Eventually, it's age/declining popularity that eventually moves them on from porn though (if other reasons haven't done so already), as the latest batch of pretty young porn actresses are always around the corner, cutting into the older gal's popularity.
A few of those end up 'retiring' to the brothel/strip club industry, and a few do porn as well as brothels/strip clubs. Do a google search for 'porn stars that work in brothels', you may recognize a few of the names... some of them have 'retired' to the brothel industry due to age, of course.
Then there's the whole 'independent escort' thing... a number of porn gals have done this on the side, capitalizing on their popularity to charge well over $1000/hr for the privilege.
But enough about money as a motivator.
That being said, I"m sure the MC would do all he could to keep D to himself, UNLESS he's been developing the sharing route... even then he'd want D to be the one she comes home to every night. In the scenario I'd like to see, Jennifer and Elena would be sleeping in the same bed as D and the MC though... and D would love them both for it! The MC might need them to play the field a bit though, just to give his dick a break every now and then. Keeping three pussies happy is exhausting!
Keep in mind that Elena's been nudging D down the 'bi' route...