Why does my baby resist her crib during naptime?

Crib and Nap. You are probably responding to her cries too quickly. It is a learned response for the baby. She cries and you run in. The more she cries, the more you run in. I say, put her down and let her cry for a while. Let her see that she does not always get what she wants with the crying. Otherwise she is simply training you instead of the other way around.
She covets cuddling. Infants are born with various innate personality traits. Some crave more intensely the tactile comfort of cuddling or motion--neither of which occurs in the crib. Also, for the slightly older baby, she may experience what has been labeled as "separation anxiety". Whatever the cause, this usually triggers "parental anxiety"! yet there is no harm in allowing her to fret briefly before settling down.