Dear all, canon law makes it quite clear that the baptised of any denomination may be given a public requiem and that the final decision lies with the local Ordinary. Here is what canons 1183 & 1184 say:
"Can. 1183 §3. In the prudent judgment of the local ordinary, ecclesiastical funerals can be granted to baptized persons who are enrolled in a non-Catholic Church or ecclesial community unless their intention is evidently to the contrary and provided that their own minister is not available.
Can. 1184 §1. Unless they gave some signs of repentance before death, the following must be deprived of ecclesiastical funerals:
1/ notorious apostates, heretics, and schismatics;
2/ those who chose the cremation of their bodies for reasons contrary to Christian faith;
3/ other manifest sinners who cannot be granted ecclesiastical funerals without public scandal of the faithful.
§2. If any doubt occurs, the local ordinary is to be consulted, and his judgment must be followed."
The Queen was not an apostate, heretic or schismatic (one must first be a Catholic to meet those categories) nor was she a manifest sinner.
In addition, the local Ordinary has given permission.
IT IS THEREFORE ALLOWED.
THAT IS THE END OF THE MATTER.
Now, for goodness sake, find something more sensible to argue about.