Violent meltdowns

Hi, my 9 Yr old daughter has been diagnosed with High Functioning autism after a 3 year battle to get help and assessment. She has daily violent outbursts, mainly if she cant get her own way, or if she's being chastised for something or if something doesn't go right. She also won't follow any rule or boundary despite us putting endless amounts  strategies in place over the years. She torments 4 year old brother daily. My worry is how she will be when she hits her teens and also that my son is starting to copy some of her behaviours.

I am wondering if anyone else's child has outbursts mainly when they dont get their own way or when they are being told off?

She is also is verbally abusive to me and her father regularly when in 'the anger  zone' prior to an outburst, she is always hyper and on the go. She attentions seeks from peers and family. She prefers 1 to 1 friendships.. 

I feel both my children's and my families and mine and my husbands lives are ruined due to constant battles and daily struggles.

Any advice or anyone in the same position I would love to hear from you,

Thanks for reading,

Suzi x