Need Advice!

About two weeks ago we found out that Dora the Explorer and Thomas the Train were coming to a city about two hours from ours.  We decided to take Marlow as she is a MASSIVE Dora fan.
On Monday my Great Grandmother died.  Grandmama has always been closer to me then my actual Grandma.  The last eight years or so she has suffered dimentia and the last year she has lived in a hospital.  I continued to write letters and send photos but I never saw her and Marlow never met her.  Its heart breaking and I've been crying and barely sleeping for days now.
Today I found out that Dora and the funeral are on the same day.  In two cities that are quite far apart.  One is in Saskatchewan and one in Alberta!! 
Do I dissapoint Marlow?  I'm not sure if we will ever get the opportunity to see Dora again while she is so enthralled with her.  Or do I go see Dora and swallow my pain and regret at not going to the funeral?  Do I honour the living or the dead?  Do I selflessley do as we promised our daughter or is this something I should be selfish about??
I'm so freaking confused!