Do I tell her tomorrow that if she would like to fly up there with me I will book the flight and pay for it? (she asked me to call her with my plans as to when I'm heading up there)
Vince, first off a thousand hugs to you. I am so sorry for your loss. Truly am.
As for asking her to join you, I think you are fine. Ask her, that's all you can do. Yes you can definitely pay for her. Remember when you book the flight to ask for the Special Fare that most airlines have for set aside for just this sitch. I don't recall the name for it, tell them that your Grandfather has passed away...I have had to use it in emergencies.
I'll be thinking about you...take care...and we're here...