living in a shellWhen Madoka runs away with Sayaka's soul gem, and her body falls to the ground, Kyouko begins to reevaluate her life decisions. She realized for the first time that she is now a zombie. She has become a shell in order to have super powers and strength. Kyubey explains that magical girls only have control of their bodies within 100 meters of their soul gems. This means that their soul was literally taken out of their body and put into the small glass jar. Without the soul gem, their bodies would stop working.
Kyouko explains later on that she is "going with" the news about her body. She realizes that in order to have the powers and strength that she has, her body needs to be more indestructible. This shows her mental strength compared to other characters, like Sayaka. Sayaka allows a witch to cut her body up as she laughs because she can no longer feel the pain. Kyouko tries to intervene because she understands that is not good for the body, even if it is just a shell. However, Sayaka doesn't allow her to get in the way.
Although Kyouko had a rough life, and has no one anymore, her mental strength is still great. She is able to pick herself up, even though she will rarely fall to the ground. Her soul is strong, which is why she is able to understand and appreciate her soul being detached from her body. Her body is just a tool that allows her to do what her soul needs or wants her to do. This is a big reason why I don’t think Kyouko would ever become a witch. She is too self-centered in her own mind to lose herself and her beliefs to grief.