4 year old separation anxiety?

[Pleasenomorecheese]

DD has always either Co-slept in our bed or I’ve slept in her room if she woke up. I’m just looking for suggestions for how to break this habit. She gets so upset if we say she needs to sleep in her room on her own and she seems to wake up like clockwork at 12.30 every night and calls for me.
has anyone been in a similar situation and resolved it?

DS is a few months shy of 4. He coslept until he turned 3 because we only had (space for) one bed in the house. Now we're in a 2 bed house and he falls asleep in our bed, DH carries him into his own bed and he stays there until anywhere between 2 and 6 a.m. when he comes back into our bed. This is a happy resolution for us for now.

What's your bedtime routine like?
What are you looking for in terms of resolution? (e.g. DD in her own bed all night / in her own bed until a certain time / falling asleep by herself..?)