I agree with what appears to be the general consensus... unless she feels motivated and wants to get healthier, she won't. To address the diet issues, shop together in the fresh food stores, take a cooking class. To make it fun, cook the healthy meals nekkid (or in sexy undergarments/pj's if she's uncomfortable). It eventually leads to
wanting to make healthy meals. But don't cook anything that splatters
As for exercise, I heartily agree setting a fun vacation or outing that you're not in shape for now and work towards it while dropping the spare change in a jar. Then you don't get the money before you meet your health goals. Sometimes you just have to do your own thing, though. My ex encouraged me all of the time and only ended up with me feeling miserable and persecuted. It took him dumping my fat behind and me getting angry enough with myself to join a gym and burn off my frustration productively. I've lost 5 sizes and 60 lbs since we broke up the first time. I love watching his jaw drop and we're good friends now. But it was something
I had to do for myself, alone. That's just me.
But, no matter how great I feel that I look now, every time my cycle rolls around I feel disgusting and bloated. I switched my b/c to one where I can cycle 4x a year instead of 12x. Which greatly decreased my side effects and those awful times where all I can do is cry and feel self-conscious about everything. Many, many fewer hormonal issues and weight fluctuations.