Please please someone advise on 20 month old bedtime routine

[Mariacbw]

Up until a few weeks ago DD 20 months old went toned with no fuss. She said good night, gave us a kiss, brushed teeth, into cot, waved me bye and went to sleep.

Over the Christmas while me and DH were off work, DD spent more time with us as we had holidays from work. One night she resisted going to bed and it's just got on from there, any sight of pjs, nappy changing she cried historically so getting her ready for bed is now a real battle. Once in the cot she refuses to lie down, and just cries and cries and cries. Lasts up to 2 hours.
Bedtime routine hadn't changed, prep for bed at 6.15, in cot at 6.30. Has approx 1.5 hour nap after lunch.
This has been going on for weeks, I thought she would Of caved by now. Any suggestions???
I did wonder if she's outgrown her cot, does that happen? Would she know? The thought if putting get to bed fills me with fear because I can't imagine her staying in it for longer than a few seconds.

Does she still go down for her nap ok or is she also resisting?
Did anything happen on that first day this all started?

We do the same wind down each night so ours know the cues....dinner, bath, pjs, story time snuggle (2-3 books) by book light in darkened room, song, down for bed. The book bit they look forward to and because its a quiet activity it primes them for sleepiness.

Also perhaps 6:15 is too early? My 23 month old goes to bed between 7:15-7:30ish most nights and has for many months - sometimes later if he had a really long nap (sometimes earlier if he had no nap). Our routine stays the same no matter what time we start it IYKWIM? I always aim to have at least 5 hrs min between nap and bed.

We put touchy-feel books and sound-button books in our sons crib so if he's not tired or if he wakes up early he has something to do. He often falls asleep fiddling around in his crib that way.

Our eldest never grew out of his crib - we moved him to a bed because he brother needed...so he was moved at about 2.2 years. Our youngest still seems content and we wont move him for a few more months if possilbe. It was a challenge to move my eldest to a bed - as you say he didn't stay in it immediately...just remember "this too shall pass"

She raids the nap times at home bug not at nursery. No, nothing other than her saying mummy and appeared she wanted to stay with me. Nothing happened other than me giving her too much attention probably, however that was because it was so out of the ordinary. We have both been very firm and giving the same message.

When reading books, are yours in bed or sat with you? We've stuck to 6.15 / 6.30. 1. Because she's tired at that time and 2. Because I'm a nurse so start work early, DD Also has to get up because DH is working nights. I'm reluctant to think it's the time because surely one day she wouldn't change so much but who knows - toddlers are a mystery!

I've just been to check on DD, crying for nearly 1.5 hours now. As soon as I walked in; she's excited, running back & forth across the cot but looks exxxxtremely tired.

We still have our sons rocker in his room, so we read sitting in the chair with a book light so its dark - rock, read -he knows a song signals the end.

He is much more cooperative than my elder son though. He was very challenging at bedtime - we would rock him to sleep TBH and weaned down to sitting with him quietly in the room not engaging (I would pretend to fall asleep myself!). Otherwise, he just would just get so worked up to a point where we could see that he could not calm down and needed help. That was our parenting choice though and I know others would frown on it. We just were not willing to let him crying and cry at that age. He did grow out of it eventually [unhelpful]

Whatever works!! They'll always grow out of it, it just depends on your personal preferences are & what your wiling to do. Tbh, if it wasn't for DH I would be rocking DD to sleep but he won't have it.