Does she deserve a second chance?

Alright, so i'm not going to go into the full story but this girl who i thought was one of my best friends lied to me over something stupid. When i confronted her about it she basically told me that i was never a good friend and that she never cared about me or our friendship. So yesterday i seen her at a fair and she looked at me and smiled and waved but not in a bitchy way, in like a ohh hi way. Should i forgive her?