I wasn't basing it off of ship speeds. A ship traveling for eighteen days straight could get across hundreds of systems, because of hyperspace and space-compression and all that. I was basing it off of the speed of radio waves, the speed of the telemetry transmissions.
She sends the first right after her power goes out. It takes x-amount of time to reach Delta Base, because we don't know where she is in relation to Delta Base. Then, roughly one day later, the next message arrives. That means she traveled the amount of space it takes light to travel for one day. Roughly 0.003 Ly, or 86,460 Ls. That's about the time it takes to get about two or three planets away from the central star, I think.
So she travels this amount, finds the ship destroyed, and panics. She probably spends an hour or two crying, hyperventilating, screaming, cursing, etc. It is at this point that she sends the second message, and it arrives one day after the one she sent earlier, anywhere inbetween ten minutes to twelve hours earlier. Then, logic sets in and she decides to move on, attempt to survive. She travels the length of the system, picks up an ELW on her scanners, and makes a choice. She sends another message, for recording reasons, and it arrives about eighteen days after the last message she sent.
60*60*24*18*300,000 = 466,560,000,000 km @ 300,000km/s, or 0.05 Ly.
Basing this off the fact that the average width of a solar system is roughly 2 Ly, I figure it's maybe three to four planets away from where she found the debris of the attacked ship. One should note that most of a solar system is empty space, so distance between planets could be huge in order to have a stable system that doesn't rip itself apart. Equipped with a hyperdrive or FSD (take your pick), the sidewinder could easily fly that distance in less than an hour, conserve a bunch of fuel, and find this planet.
I think it's something to consider.
Ammonia are very attractive to look at though
