I am also diagnosed, since 2010, with moderate obstructive sleep apnea syndrome. I have a CPAP machine. And she definitely has the classical symptoms as described by Kingpin. She definitely should go for a sleep study.
Classical symptoms present themselves by the inability to sleep or as is probably in your case the inability to complete a sleep cycle due to an "apnea" (stopage of breathing in the simplest defination). As someone who has severe sleep apnea and is currently litigating with a diability company over its affects, the autonomic nervous system either wakes someone up or keeps them awake upon the occurance of an Apnea. This is the body's fail-safe system. I've been tested at over 220 apneas a night. My CPAP machine is set at 16.
I'm not going to attempt to diagnose anyone, especially on a three line description.