Repeal Royal Marriages Act & Amend Act of Succession
The Royal Marriages Act was seen as a stupid law when it was passed in the 18th century by MPs. Does the Queen actually keep track of the descendants of George III whose marriages she needs to approve? The law was seen as a joke by MPs at the time and is a bigger joke now.
Also in the 21st century isn't it time to remove the succession where a younger brother takes precedence over a sister. Since we have two male heirs with no older sisters isn't this a time to do it as well. It would have to change it to being from a certain monarch after Victoria as we would have the descendants of Kaiser Bill as our monarchs. As our Queen has 8 grandchildren it could be from her descendants or George V as we still have living HRHs descended from him.
Why does this idea matter?
I think the second idea is as it would be modernising the monarchy and doing it at a time when no young woman would suddenly find herself being a future monarch as in Norway.
Also it would be a good idea to change this before William and also Harry marry and possibly have a daughter as their first born.