She is not a reservist, she's active duty and works a desk jockey MOS at a base in the middle of nowhere.
She's on track to be a terminal lance, as most of the Marines that end up like this are.
Very few active Marines make it to this level, and those that are on the edge know it, and are constantly reminded of it until they fix themselves or they are on their way out the door. Reserves on the other hand, this kind of ****, although not to the exact extent is far more common. I'd say overall the Corps has far fewer fat bodies, but we're also a far smaller force, so take it for what it's worth. I'd like to see some DoD statistics but that will never happen.
However, I've seen solid Marines given the boot for just being unable to tape, regardless of their actual PFT/CFT scores.