Question

Is a 740 overall test score on my sister's PSAT good or bad?

Evidence Based Reading and Writing Reading Test Writing Test Mathematics Math Test Total Score
390 19 20 350 17.5 740

Evidence based Reading/Writing = 390 pts., Reading Test = 19 pts., Writing Test = 20 pts., Mathematics = 350 pts., Math test 17.5 pts. Total score = 740

is this good or bad? she needs to know now.

Answer 1

Although this isn't necessarily bad, the PSAT/SAT/ACT just show how well you test/study for tests. I would recommend looking at schools she plans to apply to, and see what their requirements are for SAT/ACT test scores, and then study if needed. 

Answer 2

740 SAT Score Standings. Out of the 1.67 million test-takers, 1601380 scored the same or higher than you. You can apply to 1312 colleges and have a good shot at getting admitted. You have a very low chance of getting into 918 with this score.