There are three basic ways to deal with this behavior (there are variations on a theme, but still - imo - three basic responses.)
The 'adult power and authority' approach
You are the adult, and you can say, "No, get it yourself." You can say it matter-of-factly or empathetically and kindly, but that's what you're saying, and she can obey or do without. No reason to argue (it takes two to argue). If she raises a huge stink, she can get a time out. This will teach her that she can, indeed, do things for herself, and with much less conflict.
This is a common and direct way to solve this problem, and has been used probably since language began. We all do it to some extent. When my mother wanted some peace and quiet, she'd sent us outside to play. If we complained that it was rainy, she'd remind us that we weren't made of sugar and that we would not melt.
Much of life is like this. We deal with employers and other people in a position of authority over us. We really need to get used to it.
The 'all feelings are created equally' approach
The way to deal with an unwanted behavior is to find out what your child is actually experiencing when making the undesirable requests and deal with that core issue. It's more labor-intensive, but it's also very affirming to the child.
If she is asking because she feels the need for validation ("prove that you love me/that I'm worth loving by doing what I ask/tell you"), then you need to see to it that she's getting the validation she needs in a more appropriate manner, e.g. you show her that she's important to you by taking time out of your day to read to her, to play with her, to do things that matter to her and make her feel loved.
If she is testing her social structure and her ability to control others (for whatever reason), that needs to be addressed. There are appropriate and inappropriate requests in social structures. To reduce people who love you to a servant status is hurtful and, in the long run, unproductive to both parties (it is an anti-social behavior, so to speak.) As you yourself stated,
In my opinion she should do those thing by herself and not even think to use me to do it for her.
There may be other reasons for her behavior. The point of this approach is to deal with the underlying issue in an empathetic manner. Maybe she is mirroring behavior she sees elsewhere. Who knows unless that is explored?
The 'I'm not going to deal with this now/life is hard, and then you die' approach
No one gets their way all the time, which is an important lesson to teach, and the sooner we make peace with it, the less conflict there is in life. This approach is best for those with an iron will and a good sense of humor (not sarcasm, unless your child loves sarcasm.) Examples of this approach might include
Child: Mom, my fork fell.
You: Isn't gravity amazing? If you drop your fork, it will fall to the earth 100 times out of 100! The story goes that Sir Isacc Newton was asleep under an apple tree...
No, I mean, would you pick it up for me?
What will you give me if I pick it up for you?
What? Why should I give you anything?
You: Because nothing is free in life. (Life is hard, and then you die.)
Though this approach doesn't validate your child, it's often interesting and makes a point in a non-threatening way. It's not directly "Do what I say, I'm the adult," nor is it as labor intensive as "What are the feelings that are driving that request". I recommend judicial use, and only if you know for a fact that your child feels much loved by you 99% of the time.
