How do you spell Kristen in Chinese?

There are a lot of variations out there for the name Kristen (or any variation of the name Kristen). The popular one used for celebrity Kristen Stewart is:

克里斯汀 (ke4 li3 si1 ting1 - in Mandarin pinyin pronunciation)

If you do not like this version, the fourth character seems to vary.

There is no correct way to translate foreign names to Chinese since it is usually translated phonetically. If you do not like your name, you can always change the chracter with another character that has the same or similar sound, making sure that the characters you use do not have an overall negative meaning.