Our 18 month old dd has been 'singing' herself to sleep (mainly a 'mash up' of Twinkle twinkle and Baa Baa black sheep ) for some months now. She's seemed quite happy so we have left her to it- just popping in to reassure if needed i.e if singing turned to crying or to check on her. Usually she'd sing for about 20-40 minutes and then doze off. The last week or so she's been up for hours though! Tonight she's just gone to sleep at 8.45 and we put her to bed as usual at 7pm. Last night she was still up singing at 10pm. Is 7 pm too early do you think? or is this just a phase? Its absolutely shredding me as I have to use the evenings to work from home and I can never relax until she is definitely asleep!