I mean, sure she's not as useful as a normal sapphire but think about this; if Padparadscha was directed to predict something that happens somewhere else she could be the ultimate detective. Imagine Padparadscha on earth predicting events happening around beach city (or potentially even the world) in only minutes past real time not to mention that unlike other sapphires she wouldn't be guessing at which of nearly limitless possible futures would be happening but could give you 100% accurate information on an event that just happened.

Like imagine a world where Padparadscha predicts a murder minutes after it's happened and can point out exactly who it was and give an accurate detail of them to authorities.

That’s a cool idea, but unfortunately, I think that sapphires can only see things that pertain to their immediate area. A regular Sapphire wouldn’t be able to predict the events of a murder on the other side of Beach City, but they could predict seeing it in the paper the next morning; similarly, Padparadscha would mention the headline while everyone is already discussing the news, but she wouldn’t be able to see anything that she wasn’t present for.