Donna has a MacBook and it has trouble waking up. Leo says that could be due to her Time Machine external hard drive. She should try disconnecting it.
Sometimes Macs will wait until the drive spins up when it's asleep. OS X Yosemite has a safe sleep mode, which is a very deep sleep when the battery either runs low or is idle for a few days. It copies memory to hard disc and shuts everything down. It's like Hibernating in Windows, and it takes awhile to get going. Leo's not a fan.