Hi nellia07! Our experts weren't able to post directly, but they sent a long a reply to your question:

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We're sorry your daughter has chosen a violent way of expressing her desire to stay with her grandmother.  What you described is not unusual for young children, that is, their need to attach to someone to the exclusion of everyone else.  Having one significant attachment is much simpler than having several. Two-year-old children aren't very flexible because they haven't had much experience in life and can't anticipate outcomes as easily as older children.
 
What is most important here is to allow her to have her attachment but with limits.  If your mother is your primary baby sitter, the transition will be much more difficult, so consider another sitter.  Then it will be important to limit for a while your daughter's contact with her grandmother to help her ease the loss she feels when she is forced to leave her.  She can certainly have a good relationship with her grandmother when she is a bit more mature and can handle separation more easily. 
 
When you do visit your mother, begin preparing your daughter for separation by warning her 10 minutes before it is time to leave by saying, “We will be leaving in ten minutes, so let's start getting ready.  I'll set the timer so we'll know when it's time.”  This warning allows your daughter to prepare herself mentally to leave and is a signal for cleaning up, putting toys away, and getting last hugs.  Then when the timer rings, say, “The timer says it's time to go now.  Kiss grandmother goodbye and tell her you'll see her again soon.”
 
If your daughter resists simply repeat what you have said and then pick her up, facing away from you so kicking and head butting are not as easy, and leave.  Repeat this action while praising any of your daughter's cooperation by saying such things as, “You kissed grandmother so nicely. That says you're ready to go home.”  Time and maturation are on your side. Stay the course…patience will be your best friend!