@maxinvasion First: Take away her day nap, if you need just do quiet time where she reads or plays quietly. Make sure you tell her it’s quiet time and get yourself some peace; you also don’t want her wearing out.
Next: bath and bedtime go together like pb&j. The hot bath stimulates what sleep scientists call a “thermal dump” and helps them to sleep better.
Ambiance: set the mood for sleep right after dinner, lights go dimmer, tv is lessened or you set a time, like “10 more minutes and bath time”, important that lights go down, the air temp gets cooler in the house conducive for sleep.
Food: have it be about 45 minutes to an hour before bath so that you don’t risk the pee in the night need (although sounds like she’s possibly in pull ups).
Lights: no lights, use blackout curtains, no nightlights. Sometimes street lights or even the moon can creep in the sides or part in the curtain so check that. Light is a big way to wake someone up.
Sounds: we use a big box fan you can buy for like $30 at any store. That helps to cut out any extraneous noises that can wake up your kid. Sound is another biggie that can wake up someone.
Hunger: make sure they aren’t hungry or thirst but limit drinks before bed to a few sips. I like to give my kid something handheld like a slice of raisin bread if she’s hungry before bed. Eats it and takes a couple sips of water and she’s off to sleep. It gives enough calories to get through the night if she ate most of her dinner. Hunger is another biggie to wake someone up, it’s uncomfortable to have your tummy growling.
Temperature: temp is another big factor in sleep. Too hot wakes you up, too cold too. Setting the home between 68-72° is ideal. Make sure she has access to blankets in the bed and that they stay on, often at this age they kick them off and have no way to pull them up well enough and they wake up. Or they get too hot and wake. Be sure that it’s ideal blanket situation. Maybe less clothing to sleep in if that helps too. Clothing Bunches up and our kid is ok in a t shirt and undies. Sometimes takes the shirt off in the night, so if more comfortable, just the undies or pull up is ok too.
Final note - Bedtime routine is key: keep to the same times roughly, try for 12-14 hrs at this age, it weans out as they get a bit older. Keep the same bath, story or song, a hug and kiss and bed. These things are primers to set the mood that sleep time is here. If you consider all the things that can wake up a person and her actual sleeping conditions, then it should work itself out again.
Resource: I learned all I know about sleep from listening to Dr. Matthew Walker podcasts and youtube interviews. He’s a sleep researcher and wrote a book, I learned about my sleep and translated that to my kid. It’s not perfect, but works like 98% of the time. Check out one of his many videos:
on Andrew Huberman’s show (neuroscientist)
Edit to add for your current situation-
With your bedtime she should be awake for at least 5-6 hours before bed to be sufficiently tired. Your naps are probably geared for when she was younger and needed more sleep overall. Sleep times need to adjust through their childhood. A 11am-1pm nap might be ok, but honestly I’d cut out the nap at this age and go for quiet time for an hour, because when you nap it’s usually 3 hours, that won’t work with your bedtime.
If and When she wakes up: nicely but firmly say, you need to go back to bed, and softly walk her back. Say “I’ll tuck you in but I need sleep too. Good night. “ then leave. If she says anything just reinforce kindly and softly that you all need your sleep and it’s still night time.
The Talk: You need to have a day time discussion about what she’s doing at night. Tell her she’s a big girl and needs to sleep on her own and that you and mom also need sleep. Tell her it helps everyone when you get sleep, that if you don’t get enough you feel grumpy and tired to do much. She will consider that to some degree even may understand and empathize. Surely she doesn’t want mom and dad grumpy or too tired to play.
Good luck!