My Little Pony and now Frozen are the two flavors of the month for my daughter. She's like me in a sense, she'll get engrossed in a topic/character for a period of time as much as you possibly can, and then 6 months down the road it's dead to her. She's done that her whole life, whether that be Tinkerbell, Scooby Doo, Strawberry Shortcake, etc.
As for gaming, it does get easier as they get older although my time is still limited due to schedule/work. I average about an hour or two during the week. Once they hit the magical age of say 5, where they can entertain themselves for long stretches, it opens up alot of time.