My 12 week old has been waking very frequently at night for the past couple of weeks. She generally goes to bed around 8pm and initially sleeps for anything up to 5 hours, but then she wakes every hour and a half before getting up for the day at 6am. She used to wake only twice a night, and although I feed her when she wakes (quickest way of getting her back to sleep so I can go back to sleep) she rarely has much, and I'm fairly sure she's not waking due to hunger.
She's breast fed and sleeps in her own room.
Any advice about how to make her wake less frequently?