Hi OP. Sounds tough, i've been there to a point (my oldest has ASD)
Can i ask what the routine at home time is, when you all get in?
If she is suffering the 'bottle of pop' explosion at home, it may be there are some sensory strategies you can put in around home time/getting home that might help her with some emotional regulation.
I'll tell you what i did, but you'll have to find out what your DD needs as they're all different.
When i first picked DS up, we would always have a HUGE hug while standing in the playground, he needed the pressure from the cuddle, i'd also stand there and stroke his head and if i could sit on a wall with him in my lap and rock him for a little while without talking.
Once home he was allowed to go to his room with a snack, his room is set up for him so its quiet and calm. He was (and still is) always left alone for the first hour, there's ZERO demands on him, its his time to rest/relax and regulate.
Anything we ask is always done with now/next instructions so there is no sudden change, we always give count down warnings. So "dinner is in 30 minutes, i'll need you to come eat" then repeat at 20, 10, 5, 2, 1....etc
If we play, he's given a warning of stopping, and a Now/Next instruction so he knows what we're doing "We'll stop this game in X minutes, then we're going to put it away and get our pjs on for bed"
Everything is discussed in simple instruction of no more than one or two steps.
I did have some success with the 1,2,3 magic method with reasonable consequence if he was misbehaving. So "you have until the count of 3 to do X or Y will happen" (y has to be something you're willing to carry out every time)
We tried to keep the house calm, i never raised my voice. I learned to recognise when/where those meltdowns triggered. During them i'd give him his space, restrain if he got violent with NO anger/raised voices. they were dealt with calmly, and always ended with a long cuddle and a reminder i loved him, and then once completely calm, a little discussion about what happened with lots of cuddles/reassurance that i wasn't angry.
She does this with you guys because she can't help it, and because she feels safe.
Give her space
Learn her triggers.
Learn to redirect before the meltdown
Do not raise your voice
Do not chastise/punish for meltdowns.
Remain calm, reassure after the meltdown. discuss calmly.