If someone is cremated, who has the legal rights to the ashes?

Who has the right to decide burial, etc. can sometimes be a fight between family members.  Some states actually codify law as to the issue in the hopes of cutting down on litigation.  Although I am not familiar with Florida in particular, generally, a spouse has the right to decide that to do with the remains of the other spouse.  There are instances where other family members have sued to allow them the right to decide the issues here. However, the party suing may have to prove either that the decedent's wishes were contrary to the present situation or that the person entrusted with the decision showed " 'bad behavior' towards the decedent by the relative asserting a claim over the remains."

I can understand how you would like a place to visit your daughter and how difficult it must be for you.  It may, however, be just as difficult for your son-in-law to give up his wife again.  Maybe you can come to some agreement without having to battle it out in court.