I think she is talking about the digital tests, not the fertility monitor...right? Don't start testing on CD 1 with the digital tests...you'll run out too soon! Wait until atleast CD 10.
I use the Clear Blue Easy digital monitor and you should start on CD 1-5. You reset the monitor and can only pick it to begin on one of these days.
Good luck!
Depends on how long her cycles are. There is a calendar type thing on the box that she could get some answers from.
Good luck to her.