Honestly, I'm not so sure about forgiving Trixie. I mean, yes, she did say she was sorry, and yes, she helped Twilight out when she did her show. Still, she tried to ENSLAVE all of ponykind with the amulet.
To be completely honest, I'm on the rail about this. On one hoof, she was apologetic to Twilight. On the other hoof, there was that whole "make Snips and Snails pull my chariot without wheels" thing, so I don't know.