With R I usually try new things for 3-5days to see how things settle.
I find putting R to bed later is usually counter productive for us too. I tend to out her to bed for 7pm and sometimes she's asleep straight away, within 15mins or other times, like last night, she'll chat and sing until 7.30. I leave her to it, but can guarantee she'll be awake by 6am if she's asleep as late as 7.30
Hth x