I played the part of Kristi in episode 1.7 of Famous and Afraid but my name is not listed in cast. How can I get this added ?

You could submit your name on the series' episode page, if available. Please read the link below for more information.

IMDb Help Center Page:
Adding data

Note: The information on the IMDb page will likely be updated after the segment aired, which includes order numbers in the Cast section.

As far as adding a photo to a name page, you do need an IMDbPro account to submit photos. 

IMDb Help Center Page:
How do I add photos to my IMDb page?

I hope this helps. Please write back if you need some assistance with the submission.