DD constantly shouts!

[Helgathehairy]

DD is 3.5. Great vocabulary but her favourite word is no shouted at top volume. It’s constant tantrums from the minute she wakes up some days. Today is particularly bad - tantrum about her sister touching her toys, her sister singing, being told she could do something later (she wanted it right then). Basically anything that isn’t exactly what she wants, when she wants it.

It’s reached a tipping point because DH is working from home and is at the point where he’s just shouting at her now (I know it doesn’t help but it’s constant and he’s reached breaking point).

She’s been like this for about a year now. Help!