Bless you, girl. I hope you can catch a little rest. I'm so glad your mom is comfortable. Even though she's drifting in another plane right now, there is a part of her that knows you've all gathered for her. That's what's giving her peace even more than the morphine. I know you're right about her waiting for everyone to arrive.
My father did the same thing. I got a call the afternoon of Christmas Eve that he was being moved to ICU, but that he was stable. But I just knew - like you know. So I made a mad dash to pack everyone and go to Houston. It was a freak ice storm and all the freeways were closed by the time I got there. It took me almost 7 hours for a 4 hour trip, but he waited until all the kids and I crowded in his tiny room to say goodbye. He died within the hour, having gotten to kiss us all and tell us to take care of my mom. I'm praying your mom has as easy a passage as my dad did - surrounded by all those she loves.
Love to all of you.