American McGee:Actually, the game is set almost immediately after the first game. 11 years have passed in the real world – where we’re making the game – not in Alice’s world.

Source: http://gamefanmag.com/hero-worship/interview-american-mcgee-alice-madness-returns

Kotaku and Wikipedia have erroneously said that the game takes place 11 years later. So there's no need to worry, Alice isn't in her late 20s/early 30s. Hopefully this will clear up some confusion.