In my humble experience...if she is feeding herself, she will stop when she is full. Also if you are offering her some from your fingers and she's taking it, to me that is an indication that she is still hungry. Normally babies (especially one where feeding is established) will turn their heads, close their mouths, or shake their head no, or all of the above, when they are full.
I also think it's normal for her to slow down and play with the food. She is still learning with all her senses. So the touch and texture of the food is probably interesting to her.
Hope that helps...and if you're really worried, monitor weight gain...
Is she still drinking enough milk?