5 yo suddenly tantruming, advice on why andhow to hamdle

[Belleende]

So, my 5 yo has always been high energy, not the longest attention span in the world and sometimes struggles with displaying her emotions in an appropriate way.

She went through the usual 2/3 y.o. tantrum stage. We dealt with it largely by pre-empting problems, and distraction. Eventually they fizzled out.

The last month they are back with a vengeance. She gets white hot with rage with little to no warning. Lashes out and me and her little sister, has damaged her newly refurbed bedroom, and thrown a chair at the wall. This weekend our babysitter took her out and she had a major tantrum with her. Last week she was so out of control I had to physically pick her up and put her in her room.

We have created a behaviour chart, with suggestions of how she can better handle anger and frustration, but it still takes ages to get her to snap out of it.

We have not been able to figure out what triggers it, seems to be any little thing she is not 100% happy with. And also can't seem to identify any bigger issues that may have triggered it. Granted it has been a turbulent year for all, but her transition to year 1 has gone much better than I expected.

Any resources, hints and tips would be very welcome. Her younger sister seems to be entering her tantrum stage I don't think I can handle both of them doing it.