Jo - Yes, I also thought of overtiredness. That might be part of it some days but I don't think it's the whole issue as we have tried a whole range of A times before bed and it didn't seem to make a difference. She also fights her last nap of the day and often just won't take it at all so ends up being up much longer than I would like her to be. On an 'ideal' day, she would wake from her late afternoon nap around 5 or 5:30 and she goes to bed 7 or 7:30. However, like i said, that 'ideal' rarely happens either due to 45 min naps earlier in the day or refusing her catnap.
Yesterday I just nursed her and didn't offer any solids, and she went to bed at 7:15, fussed just a bit and then went to sleep, and there wasn't a peep out of her! We were doing some other things during the evening, so I forgot that I was going to move her df, but she didn't stir and I did her df at about 10. She slept through til 6, when I fed her and put her back down. I don't think she really went back to sleep, though, probably so well rested, lol, and I got up with her at 7. (She had woken early from her catnap due to a poo, so had been up from 4:40 until bedtime @ 7:15)
It may have just been a fluke, but I'm going to hold off on the solids again today and maybe tomorrow and see how she does. I'm fine waiting a few weeks to try the solids again if it will help her sleep better in the evenings!