I have been meaning to post something about this for some time and I just keep forgetting to do it, so I thought I would just do it now and get it over with. In TFoH after Birgitte is torn out of Tel'aran'rhiod and is talking to Elayne about being bonded she calls Elayne the Daughter Heir of Andor. Later in the book Birgitte upbrades her about the need to bend the trueth saying something along the lines of "Tell that women you were the daughter to a Queen..." and then agian later in the book when Nyneave says something about not being in her mother's palace Birgitte is aghast "You mean you Really are the daughter heir of Andor..." Anyway it's always bothered me that she calls her daughter heir then seems to forget she's the daughter heir...is this just a mistake in the books or is it a forshadowing that Birgitte is already losing memories and not just old ones. It's been bothering me for a while and I thought I would see if anybody has an answer...

Good question, unfortunately I've no idea. I can only guess that like you said Birgitte is losing her memories.

It's a mistake and it's corrected in the later editions. Quoting Encyclopaedia WoT:

 

"Birgitte tells Elayne, "You saved my life, Daughter-Heir of Andor. I will keep your secret and serve you as Warder." But later Birgitte does not believe that Elayne is the Daughter-Heir.

 

The sentence is now corrected to read, "You saved my life, Elayne. I will keep your secret and serve you as Warder."

Thanks it's nice to finally have that cleared up I always wondered if it was a mistake or not. There was another one that's similer to this were Elayne says something (in her head) that it would require Mat Cutthrins luck ( sorry if I spelled that wrong) but later she's cunfussed when Birgitte mentions something similer. Probably another mistake it's amazing the things you notice when you read the book enough times, or in my case listen I have every book on audio and have listened to them MANY times. Thanks for clearing that up though I always wondered. :)