If my daughter's umbilical hernia becomes temporarily incarcerated and causes some discomfort should i take her in to the er after it has released?

Depends: On what it took to reduce it. Usually an umbilical hernia will protrude but be readily pushed back in with little effort. If she had a very hard mass protruding and the hernia is small then there may be a risk for incarceration but if it has reduced (i.e. gone back in) she is safe. Most hernias have almost constant protrusion as depicted. They usually close on their own over time.

Follow up with PMD: for surgical referral would be a reasonable course of action following successful reduction of a strangulated hernia. If symptoms recur prior to the appointment, an ER visit would be warranted.