Sleep regression or separation anxiety - 2 yo

[Violettas]

Apologies for a long post but I need advice from anybody that experienced similar behaviour of a 2 yo. My DD is 25 months old and since very early (I think from 5 months) she had been a great sleeper and slept through the night. Me and my husband used to cuddle her to sleep until she was around 18 months but since I fell pregnant again my husband trained my DD to fall asleep independently. We follow the same routine every night 6pm: bath, milk and story, cuddles and then we put her to bed and leave the room around 7pm (room is dark and always good temperature for her). She used to fall asleep perfect and would sleep till 7am (she would occasionally wake up if she lost her dummy, but giving it back to her would solve the issue. To add - she also naps during the day from around 1pm -3pm
For last week my daughter turned into a nightmare when it comes to sleeping. She demands for her daddy to sit in the room until she falls asleep and it sometimes takes her 3 hours to actually fall asleep. If he leaves the room she screams as if somebody was torturing her, she even climbs out of her cot over the rails and screams until my husband goes in the room and sits in the chair (she doesn't want me, just daddy).

Question is - why she started behaving like this? Is there anything we need to do or is it just a phase in toddlers development. We can't let her cry it out as she wakes up her baby sister (3m) which is not a great sleeper at the moment and doesn't sleep during the day, so I'm trying to make sure she doesn't get her evening sleep disrupted.

I really don't know what to do, every evening is so stressful for me as I know my husband doesn't get much rest and I can't do much because I wake up at night to feed the baby plus my toddler just wants her daddy.

PS. My husband had to go away for a week to attend a funeral and I was at home alone with both girls and one night my older daughter behaved the same way but I had to let her cry herself to sleep as I was dealing with the baby. She feel asleep after crying for 5 min. After that episode (a month ago) she was back to normal, but now for last few days it's every evening story.

Please Help

How many molars does she have?

Very similar routine as my DD (now 2y7m), who was also easy to get to sleep independantly. She cut her first molars around her 2nd birthday and it was honest-to-God the worst 4 nights sleep I had in her life! She was clip by and tearful and unsettled - it was awful to go through.

She has just recently gone through cutting (or starting to cut, not fully through yet) the second set of molars. Not quite as intense this time around, but more prolonged agony.

What are her language skills like? You might be able to talk to her and ask her what is wrong.

"clip by" = clingy (autocorrect fail)

Thanks for the message. I will check her molars, she doesn't show any signs of teething (mabe just drooling a bit). Did you give anything to your child? Calpol or bonjela?

She has great language skills, she is great during the day, playful and happy. It's just nights that seem to be difficult. Every time we ask her what's wrong she just says she wants to cry....

Went through exactly the same thing this time last year with my DD who was 25 months at the time. I was at my wits end after weeks of being held hostage in her bedroom for hours at bedtime and during the night. It was so upsetting (and out of character) to see her so hysterical. In desperation we decided to do controlled crying. I told my husband to prepare himself for a couple of weeks of no sleep but to my great surprise it only took one or two nights for her to get the message!
In addition to this - and again I never would have believed it would work - we ditched the dummy. This was on the advice of a sleep consultant my friend had used...apparently dummies are a "sleep prop" and can actually disturb sleep, even though to us they appear to aid it. Well we've never looked back and DD has been a good little sleeper again ever since. Good luck - I really sympathetise - horrible thing o go through xx