3 year old waking 6+ times a night

[Rumpleteezer]

Any help/advice appreciated please! My just turned three year old has always been quite a tricky child, she was a reflux baby and didn't sleep for the first six months, then slept amazingly from 6m to the moment I took a pregnancy test (age just over 2)! Then 6 months of 1/2 wake ups per night requiring water/a toy. I'd go in and cuddle her in the chair, then put her back down (no talking etc.). Since our baby arrived 9 weeks ago she has been up most nights, tonight she's up to 6 times! My husband and I are on our knees... our eldest 5yo has also been waking up due to the sleep disruption I think?

How should we deal with these wakings? She has a sticker chart and gets a smartie when she sleeps well but when we ask why she's awake she says only 'don't know'.

She's also screaming every night and won't go to bed, but he bedtime routine has changed as now my husband puts my older two to bed so I can feed an increasingly tired and grumpy baby.

If you've read this far thank you and please send advice/tips my way!

Bumping for help please. HV suggested everythjng we are already doing. Current issue is bedtimes; she’s waking my eldest who is exhausted with school starting back who is in turn crying, then also impossible to settle the baby... I end up running between their rooms the whole evening! Eldest really needs her sleep and having to re-settle the baby usually just leads to her being up another two hours overtired and screaming later.

We’ve tried the 5/10/15 minutes going back into her room and if we are lucky it’ll be the 10, if unlucky she will have just made herself sick... so stuck at what to do as in often putting all three to be by myself.