My DD is 3.5 and DS is 10 months.
DD is in bed between 7 and 7:30 and DS between 7:30 and 8:30 (depending how long it takes me to get him to sleep)
I've always got cooking, cleaning up, toys to put away, paperwork to file, clothing to fold after that but rarely do any of it. I like my quiet time.
Usually I'm in bed between 9:30 and 10:30 as I'm up 2-6 times a night to DS.
I find though that I stay up until 10:30/11 if I've had a rough day and have only gotten DS down at 8:30, as I'm not ready to give up on the day and start the next day 'sooner'
On that note it's been a good day but DS is sick and has me up for a 2 hour party at some point over the last 5 nights so I'm off to bed now at 10:15.