I am so sorry for your loss
With regards to your toddler, unfortunately sleep training once in a bed is infinitely more difficult than when in a cot.
Im going to answer this on the basis to you wanting to deal with your toddlers sleep. But please don't think I am insensitive to what you've all been through. It might be that you are not strong enough to sleep train right now. And that's ok, in which case it's coping strategies you need. To sleep train you need high reserves of resilience and patience to be calm and consistant.
So I would suggest Rapid Return.
It would involve setting very strict boundaries. Explaining them in advance with your toddler and setting your expectations. A mantra is useful for this, make it cover all of your expectations. For example: "Sleep time now, you must lie in bed quietly at sleep time. Nan night".
Significantly shorten bedtime routine. Making it bang-bang-bang, one think after another without any faffing. Bath, straight into nightwear, immediately brush teeth, immediately read pre-arranged book (no faff choosing, for now), immediately into bed. Out of bath and into bed within 10 mins. No messing.
Also, no milk at all. No milk at bedtime, no milk in the night. Explain this lots in the daytime before. Keep toddler well hydrated during the day. A well hydrated child has no reason to be thirsty at night. No drinks will be given in the night. Talk to toddler about this.
Also talk to toddler during the day about your expectations at night. Primarily sleeping on own bed, staying in bed, no noise.
So bedtime. After the short-and-sweet bedtime routine, here's what you do:
- into bed
- say mantra
- give kids and hug
- leave
- close door
Don't longer linger on leaving. Kiss, turn, go, close door. Child needs to know that there is no hesitation or movement in these boundaries or expectations of behaviour.
... But then you wait just outside the door.
Any noise, and movement to get out of bed, immediately open the door (this is the "rapid" but if rapid return). Without any conversation or delay, return straight back to bed and repeat steps above. Into bed, say mantra, kiss/huh, leave, close door.
You might literally be like a broken video on reply initially, as soon a you get to the door turning straight back around and starting again. Over and over and over and over again. Eventually, and it may be a long, long time on the first night, she will stop getting up. Eventually she will stop shouting/crying/wailing.
Throughout all of this, the pressure on her is not to "go to sleep". It is to lie in bed and be quiet, that's all. Remember thats all you want from her. If she wants to lie in bed quietly and
not sleep, that's up to get. But she must lie in bed quietly.
You would need to repeat this for any wake ups. Hence you need a lot of support in coping. You will no doubt be very tired the next day. But be consistant. Consistency is key. Don't give up. Set your boundaries of expectations and stick to them rigidly.
Within 3 or 4 days she should have established that you will not negotiate on these expectations of her behaviour, so stop trying.
Good luck!