Why wait until Primary 3? The longer you wait, may become more difficult to correct her personalities and mistakes. Then she will become a teenager, with more problems to come.
It seems that hitting doesn't work on her, and may make things worse because she has copied this behavior from you whenever she wants to get something.
You and the rest of the family must be very firm with her, and let her know what behaviour is acceptable is unacceptable and what are the consequences.
1. Lay down very clear rules at home and even write them down and show them to everyone including your girl (now she is 5 and should understand) for example
- NO hitting
- NO screaming
- Respect
etc.
2. Teach her the correct way to express herself or request what she wants.
For my girl, whenever she screams or rolls, I will NEVER GIVE IN.
She MUST say politely (such as "I want a xxx please") first.
When she wants to interrupt or scream when adults are talking, I will say NO, ONLY 1 PERSON IS ALLOWED TO TALK AT 1 TIME. WHEN X is talking, you keep quiet and listen. When YOU are talking, we will listen too. IF YOU SCREAM, we will have to leave.
After some time, she will learn what behaviour is acceptable and what is not.
3. Punishment of some form which you can choose and determine what's appropriate:
- LET HER SUFFER FROM HER CONSEQUENCE: For example you girl refused to eat. Tell her "if you don't eat, you may leave the table but no food until next meal". If she cries later, then tell her calmly that it was a choice which she made and she must keep her promises and accept the consequences.
My girl for example, when she was 2 she could understand simple instructions, 1 day refused to take her nap because she wanted to play. Of course, few hours later she cried and complained in front of me because she was too tired. I just told her calmly and firmly "I asked you to sleep but you didn't. Now you are tired and grumpy. My fault? NO. It was your choice, so don't yell at me. Deal with it, go to sleep next time." She then shut up and listened to me when when she needs to nap.
- I personally like the timeout / ignore method because it doesn't involve hitting and can be done easily at home.
Find a naughty corner or chair at home. Somewhere that is safe and you can easily keep an eye on her such as her bedroom.
When she makes a mistake (e.g. hit & scream, not obeying rules), give her the first warning (count 1) that she is wrong and she'll get a timeout when you count to 3.
Most likely she'll challenge your limits again, so you count 2, and then 3. On 3, immediately take her to the timeout spot, and ask her to stay there.
(Don't need to explain or teach at this point of time or during timeout because most likely she'll be extremely angry that whatever you say she WILL NOT LISTEN)
Generally, timeout is 1 minute / age (so 5 mins for 5 years, etc).
During timeout, most likely she will scream and shout but do not talk to her or comfort her.
If she leaves her timeout spot, quietly bring her back and re-start her timeout again and wait till her time is up. By this time, she should have calmed down a little.
Go to her, tell her timeout is over and WHY she was put in timeout & what she did wrong.
Then, she must APOLOGISE. If she refuses, don't argue but just simply walk away to let her cool down until she's ready to apologise.
After she apologises, then hug and comfort her.
If this happens in public, you can do timeout by removing her from the area and put her in a quiet & safe spot, and ignore her until she calms down.
If it gets out of control, leave the place immediate as a form of punishment.
See if this works. I've never hit my girl before, because she HATES timeout and will usually listen by 2nd warning.
4. Positive reinforcement
- When she does something good, show appreciation e.g. "thanks", "good job" etc.
- Explain in detail what she did well (e.g. you sat still and finished your dinner, which was very good)
- When she's good, spend some happy times with your daughter so she'll feel attached and secure with you.
- I will stay away from materialistic awards (such as junk foods, toys)
5. Be very firm, and do not ever given in to screams, tantrums, hitting etc.
Because your girl has learned that hitting / screaming can get what she wants from grandparents.
This behaviour must be corrected otherwise it will just get worse.
When you teach your girl, do her grandparents get in the way or try to stop you?