Translation:She forgot me, so she didn't even call.
I'm fine with the translation, but the sentence makes no sense in English. "So" means that the first part is the basis for the second part. I could understand "She forgot me so she called me to apologize," or "She didn't call because she forgot me," or "She forgot me and she didn't even call," but forgetting someone isn't the basis for a decision not to call you. If you don't call because you forgot, then you'd use "and" because one didn't cause the other. Forgetting caused both.
I'm confused about the verb appeler and the use of 'call'. Is this the American way of talking about a phone call or does it mean literally to call on (visit) someone? As an English person, I thought it must be the first, but Duo didn't understand when I said "didn't even ring" which is a normal English way of talking about a phone call.