***Adding this: She may very well be, experiencing some anxiety... since she knows she will be starting Kindergarten soon. That is a big deal for some kids and emotionally. Help her through it.
Don't scold/punish her for her behaviors now... it is emotion based, or stress possibly.
As a young child, I remember myself being 'nervous' about starting school and a new grade... so many unknowns to a young child.
And at this age, emotionally, they don't know how to navigate through their apprehensions/anxiety... they don't even know what that is, and they don't have the ability to articulate it.... succinctly either. And just NOT knowing... what school/Kinder will be like... is a big thing to not know... and it can stress a child.
Talk with her... help her... let her know she's okay... and when she is grumpy or doesn't feel well or is irritated, that she CAN tell you, verbalize it and you can comfort her.
She probably needs extra "bonding" right now... my daughter is like that when she 'needs' more bonding from me.
Kids, no matter what age, STILL need 'bonding' and comforting.... and it is manifested differently per their age-set.
But it can help to calm them and assure them... through their grumpy and not so even-keeled moments.
I know it does for my kids.
Instead of trying to do things like how Kinder will be (ie: the green/yellow/red cards.) Stop doing that... that is not what she needs right now.
INSTEAD.... I would just in a fun way, talk "about " Kindergarten and "allow" her to ask questions and to even be "allowed" to feel nervous about it... that way, she can commiserate with you about it, and get out any apprehensions etc. Make it non-intimidating.
Or... get her books on "Kindergarten" and read it together. Help her adjust.
The point is: your daughter, has a big thing coming up... Kindergarten. I think... that is the thing that is affecting her sleep and then lack of sleep and her behavior. Kids... when they get like this, can also mean that something in their life is changing... or they are stressed. The one BIG "change" in her life, is Kindergarten.
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Probably lack of sleep. Hence, she is overtired.
Animal Parade, is a good brand that makes kids vitamins. They also have this "Warm Milk" chewables which helps to foster sleep.
Here is the link:
http://www.buzzillions.com/reviews/natures-plus-animal-pa...
You can find it on Amazon as well and any natural food store or Whole Foods.
Good luck,
Susan