What you could blame her for is not doing more to dismantle the monarchy's non-figurehead powers from the inside. But what you're trying to do is something else entirely and rather gross.
But the place she sits, is from the blood of millions who were enslaved, robbed and were dealt with a rather inhuman treatment to say the least. In the process empire also justified what they did was in the past and cautiously moved away from that without an inch of guilt. It is sad to see people in India/Pakistan/SriLanka mourn for her death, a pity case of Stockholm syndrome.
If as you say, she has done good in her life, she should have relinquished the power, disowned the wealth which was directly a result of the horrific colonialism and imperialism. Or at least have some decency and apologise, give back the stolen wealth as a good gesture. Now I wonder, if she would have given up imperialism out of her own volition if she was in power during that period. I am inclining towards No.. it was convenient she didn't have to oversee those horrors.
It has been more than 70 years and even now, they hold their crown so precious adorned with the Diamonds taken away forcefully from our lands. What an absolute shame!
There are unheard horrors from the colonial countries, which will ache even the stone hearted. Bringing all this in perspective, we don't think she's Kim, but we have the same respect or the lack of it for anyone in their legacy.
The commonwealth nation should also do that. It time for the UK to move into a new era.