We're having the same issue as the OP. We'll be sailing on the Fantasy next spring break (2014). DD1 will be 12+9mo, DD2 will be 10+10 mo. DD2 is used to being around her sister and friends, so I think she'll be fine from a maturity level.
We originally booked a dummy date on our last cruise and this is our reschedule (done so we could try to get the kids in the same club). We're limited as to the time of the year we can travel due to school and activities, so spring break works best. My husband is a little nit-picky, so he wants me to contact Disney to see what they say about the 10 year old being able to join her sister in the Edge. I'm afraid that if I can't convince him that it will work out, he'll make us move the cruise out to 2015. I trust all of you to tell me the way it REALLY is.
I understand that it's not 100% guaranteed, but what do you all think the chances are of them letting my almost-11 year old hang with her sister in the Edge?
Thanks in advance!!!