Recently, if you post anything about a dentist making anything over 200k on here everyone thinks you're crazy. My dad's job puts him in a position to know the salary of dentists in the area and he has told me that 400k my first year out is definitely possible. Now 600k, if she is working 7-5 5 days a week and some on Saturdays that it might be possible.
However, I garauntee you she's not working in a glamorous location, I bet the only thing to do there on Friday night is go to a HS football game. It's all a out location and with the proper amount of research you could find a place like this, just be ready to be extremely bored after work. I will give you a tip on finding these locations, seeing as I've lived in one for 20 years I know a little bit about it. Get a map, look for a big city west of the Mississippi, now move your finger to somewhere about 3-4 hours drive away from that big city and make sure there and no other big cities near it. If you see anything that might be an attraction (lakes, oceans, mountains) then You're gunna have to restart. Once you land on a place where there is literally nothing within a 3 hour drive in either direction (we call this BFE where I'm from), then congratulations, I'm 99% sure you just found and extremely under served area and will make great money there.
Remind you I'm just a pre dent but I get my information from a much better source. Now excuse me while I go get my helmet, people on here don't take kindly to someone who says you can make a large salary your first year out.