OH GEEZ!

As one of three sisters...heres my take for what its worth...
Did you happen to mention to your daughter that her aunt had picked out that pix as a gift for grandma already? If not, IO think you should have, you did know she asked you and you you did make it appear that you were well aware it was agift from her to give your mom....sorry, but I think you owe her an apology for a) either NOT mentioning it to daughter (who YES< should have her choice of pix to get and give, BUT, I am sure she would be kind enough to step aside for that ONE pix since it was already offered up to your sister (otherwise how did your sister get the photos to review anyway) OR B) apologize for FORGETTING to say something to the bride that sis already wanted that pix as a gift...but honestly, Its a HAPPY occasion, a WEDDING, so HOPEFULLY no real angst and hurt is left and instead happy thoughts and just a forgive/forget can take place. Good Luck!