I’m just reading The Quest for Queen Mary edited by Hugo Vickers and it says this.

of the inheritance from P ML
“‘Oh the tiara!’ The Duchess smiled ‘it’s left to me for my life and then to Richards wife. But I can’t wear it, it’s too big.’
‘More like a mitre than a tiara, I remember’, said Princess Alice [Countess of Athlone]
‘Oh, much too heavy’.
‘But couldn’t you have it rearranged ma’am?’
‘Well you know I’ve already got two tiaras - one Queen Mary gave me and one he did when we married, sufficient unto the day, don’t you know. And then having jewels arranged is so expensive’.