I have an 8 month old who for the past week or so wakes up a consistent 3.5 hours after bed time. I've put her to bed later and earlier, we've done 2 and 3 naps, the routine is the same - she just wakes up and will not go down again for a couple of hours.

I'm not willing to CIO. Usually a little rock does the trick, and she goes down well to start off the night. I'm still nursing her at night because she's small and has fallen off the growth curve a bit, so sleep training to cut out all wakings isn't an option.

She may be teething - she pulls her ears, loves a teething ring - but I don't see or feel anything there.

Any thoughts on what could be happening?