Carey, If she sells it through an agent at $70K, and owes $65K, she will get nothing after paying the comissions and closing costs. If your area is like ours, and sellers often give 2-3% in concessions, I'd estimate she'll have to bring about $2,500 to closing. So, doing a short sale might actually save her some money.
If its really worth $73K as-is, and its in good condition, then, even dropping it to $65K with a short would make it attractive to owner occupants. That's a pretty small short, so I would think the bank wouldn't balk too hard at that. (Who knows, though, its a bank.) Depending on the competition, maybe dropping it a little more would generate a quick sales.
If it needs work, and especially if there are move-in ready competitors, it may require and investor. As an investor, I'd want to know my true ARV, which is probably something under that appraised value. Say $70K. Discount that 30% to get $49K. Subtract off the work needed, and that's what I would pay. Now you're talking a much more significant short.
Personally, I'd never pay FMV for a property. I'm in this to make money, and you can't make money paying FMV.