I dont think she really has neck problems since her operation in 2013. The court has never said that.
She just does not seem to like jewels very much, earrings and a bracelet maximum. I hope that next year for her 50th birthday she will wear queen Mauds diamond tiara. Atleast for some portraits.
https://www.thecourtjewel...-queen-mauds-diamond.htmlIf Charles coronation is a tiara event I hope for the emerald parue, it has been a tradition for the last two coronations, Cp Martha wore it for both occasions, but in the end probably she will not, but maybe some of the british tiaras the NRF have