5 y/o won't go to bed

[Apollon]

Help, advice, desperately needed, I have a 5 year old, my youngest of 3 and she will not go to bed, we have at least 2-3 hours of horrifici tantrums each night and its getting worse!!
She has never been great at bedtimes except when she has a sleepover with her sister, but then that starts a whole new reign of wanting to wanting to stay with her forever more.
i think my husband and I have exhausted every possible technique I can think of, even my teeneager is trying to help because she can see how mentally dreaining the evenings are.
We've tried being hard lined, we've tried being soft, we've tried everything, and at least once a night we get a visit from her during the night, but I say to her to go straight back to bed and she does it.
sleeping at Grand parent's she's fine.
She is also a selective mute and has explosive tantrums during the day for tiny things, which I'm trying to pick throught with the school SENCO.
Please help!

No idea if this would help you, but we stay with DD (6) as she goes to sleep - there's an extra mattress in her room to lie alongside her (light off) as she goes to sleep. DD panics if she's on her own (she doesn't behave particularly badly at bed time) and this helps her. Have you tried it with your DD?

My dd went through a short phase of this. We bought her a little MP3 player and loaded it with lullabies and bedtime stories. That helped a fair bit actually. I think she liked the company and distraction while she fell asleep. She has been a very avid dummy user and really struggled without that sleep cue when she stopped using it.

We also sat on the landing and so on but the introduction of some music was very helpful and some years later she still likes it

Why can’t she share with her sister? Our DD (5) hates being on her own to go to sleep as well so we sit with them both together. Am sure by time they hit preteens they will want their own space but can put themselves to bed

Sorry. Also, what sort of routine does she have? At which point do the tantrums start? Would it help to have some sort of graphic planner where she can see what is happening next and at what time?

What is she like to get up in the morning? Does she seem rested?

She doesn't share with her sister as she keeps her awake and my middle one likes her own space and when its bed time, she goes straight to sleep. I really like the idea of an ipod as we have done the the whole thing of staying with her while she dozes off.
Her routine is generally brush teeth,I read a story to both the younger ones in my bed and then they both I take them both to bed, kisses cuddles etc, they both have lamps left on in their rooms but my youngest also likes the hall light left on also, then big sis, daddy does kisses etc, about 10 minutes after, she appears downstairs crying with all types of different reasons.
Also I'm new to this, what is a dd?

It means darling daughter. Just use daughter if you prefer.

Maybe she would like to pick an album of song or stories? I am not saying it was a magic bullet for us but it did mean she was more likely to settle down herself once the stories were on. She has now graduated to a kindle fire with audible on so the stories are longer.

We started with the cheapest wee MP3 player but actually maybe a wee CD player would be easier

At five you can just set very clear expectations and be firm about upholding them. Nice routine, maybe lavender spray, a set gentle music tape then sleep. Don’t truck tantrums.