Ideally, of course, the seller should describe items in as much detail as possible, to avoid this sort of thing happening - but I totally understand that that can be hard to do, as there can be so many details to remember and in this case, you would have had to say; 'The strap is not detachable.' and frankly, who would think to say that? 
I certainly wouldn't have (although, I might now!
). 
I don't think this is buyer's remorse, though - buyer's remorse is when someone buys/bids on something, knowing exactly what they're buying (and its true condition) and then, later, decides that they shouldn't have bought it, for whatever reason (perhaps they feel they bid too high, or the item isn't really for them after all, or they just feel they shouldn't have spent the money).
This buyer just wasn't aware of all the features of the item and so (unwisely), just made an assumption; had she known, she wouldn't have bid.
Also, I presume this is a well-known style? So, presumably, as you didn't stipulate that it was a non-detachable strap, she could have done some research, or asked you about it, if it was an issue?
As chuckster says, I think she was just expressing herself and perhaps, also, hoping that you might volunteer a refund; she obviously didn't assume she was entitled to one (as the item was not SNAD and she knew it).
I certainly wouldn't have (although, I might now!
). I don't think this is buyer's remorse, though - buyer's remorse is when someone buys/bids on something, knowing exactly what they're buying (and its true condition) and then, later, decides that they shouldn't have bought it, for whatever reason (perhaps they feel they bid too high, or the item isn't really for them after all, or they just feel they shouldn't have spent the money).
This buyer just wasn't aware of all the features of the item and so (unwisely), just made an assumption; had she known, she wouldn't have bid.
Also, I presume this is a well-known style? So, presumably, as you didn't stipulate that it was a non-detachable strap, she could have done some research, or asked you about it, if it was an issue?
As chuckster says, I think she was just expressing herself and perhaps, also, hoping that you might volunteer a refund; she obviously didn't assume she was entitled to one (as the item was not SNAD and she knew it).
