My DD has always been great at going down to sleep and has also slept through the majority of nights since around 6 months.
She is currently going through loads of developmental stuff- on her knees about to crawl, babbling, cutting top teeth. This seems to have coincided with major disruption of her sleep. She screams for up to an hour after being put down at night despite being tired, and wakes up several times in the night. She also seems to be fighting daytime naps.
I seem to remember reading something ages ago about major physical cognitive or physical development interrupting sleep. Does anyone have experience of this, especially around this age? Or would you suspect another issue e/g/ separation anxiety?