4 Year Old Daughter

The mommas are so right on the sugar. Start there, take away most of the refined sugar in her diet and the fruit juices, water them down. Watch Ritz and Club crackers, they are loaded with fat and sugar too.
Enroll her in dance, gymnastics, martial arts, soccer, something where she can run off her energy.

You are not the worst mother. She just moves at a different speed than the rest of us.

I am also chiming in on the sugar as the first thing to watch. Even a little soda sent my sister through the roof as a child, so is she eating or drinking stuff you put out for company? Also, as others suggested, she may need more sleep. Perhaps try out an earlier bedtime and see if it helps?

Some kids are also just naturally hyper, but she needs to be able to control it. Maybe a beginning karate class, which would help her work off energy but also learn discipline? Still, any kind of class could help because she's going to have to learn to listen to the teacher, but at least it's more active.

My son gets hyper and is horribly behaved when he is overtired. Even 15 to 30 minutes makes a difference with him. It is so easy for him to get a little overtired and so hard to get him back on track now that he no longer naps. Also some kids are more demanding of attention--my son is much more pushy than my daughter who is younger. She will play in the same room without being right in my face constantly.

My two oldest were hyper and I'm afraid my fifth is going to be hyper. He's the most active 10 month old I've had yet. I found that my kids had food allergies which caused a lot of this. I didn't give them white sugar or fruit juice (or soda etc.) or anything I noticed caused them to be more hyper. I also made sure they got plenty of sleep at night. Good luck!

My 4 year old is generally OK, but she gets hyper when tired -- she seems happy but she is out of control; and she gets hyper with certain foods, like "cheesy" snacks with red/yellow food dye; pop or diet pop, and too much candy. I've hear of behavior problems with other food allergies too, e.g. wheat. A food diary is a good idea.

Mine definitely gets into trouble when I want time for myself. Keep things routine -- my daughter always wants to know what we are doing next/tomorrow/day after. It helps that she knows what's expected of her. If your daughter behaves better when she's pre-warned, that's great! It means she can control her behavior and needs direction from you. Good luck -- I know it's exhausting and when Mommy is grumpy from not having any time to herself, it makes the situation worse again!

If she is not already, maybe enroll her in some classes or Preschool for socialization.

Or, if she gets like this when she is tired, then she is over-tired. Some kids get HYPER when over-tired. Like my son. But he is actually very tired.

From about 4 years old, kids need more socialization/structured activity to their day.
I have found, that they just change so much physically and cognitively, at this age. Per my own 2 kids.

I like the suggestions below and also give her actual "instruction" instead of "don't be bad" you can say: "please make sure you do this...and that...". One thing that always worked for us is that we always try to focus on the positive instead of the negative such as "make sure you keep being a good girl and remember what we talked about earlier" INSTEAD of " don't be a bad girl!".

If you tell her ahead of time (pre-warn), does she listen? If she is able to control herself, then (phew!), it is just a matter of continuing to be clear and consistent.

Here are a few things which are great for every child to avoid - I'd just throw them out of your house and tell her she is allergic to them (which is true): food coloring. Pediatricians are telling families to avoid sugared drinks 100% - that means sports drinks, soda and fruit drinks which are not 100% natural. It's just so much sugar and fake stuff.

Slowly start substituting fresh fruit as a snack. and real cheese instead of 'American cheese' and whole wheat bread instead of white bread. It's okay if she eats less to start with. Cut out flavored milk - only real milk and water. Cut out sugar cereal and give her a real scrambled egg with whole wheat toast or real oatmeal (not the instant kind with flavor added - that means tons of sugar - add some brown sugar yourself - it will be a lot less than the packets even when you make it taste good. Over the weeks, just slowly add less sugar.)

My friend has 3 boys and she has to take them on 2, 1-hr. walks every day. They just need the active time. Don't compare her to other children. And keep her off tv/electronics - that makes them develop shorter attention spans.

I was going to ask about sugar and fruit juice or food with sugars in them but Jaimee beat me to it lol :P
I think most toddlers are hyper, I THINK. My daughter has a lot of energy most of the time and my cousin has 4 yr olds she watches that are hyper. I was going to suggest an herbal tea to calm her down but I'm not sure if it would just put her to sleep. My daughter is a LOT calmer and more pleasant when she eats nutritious meals in good portions (sometimes she will refuse to eat a lot)... like today she ate some chicken veggie pasta I made and she ate a lot of it and was in an awesome mood. It was great. I've seen a lot of posts that suggest keeping a journal to see if it comes at specific times or after eating/drinking/doing something specific.