My children evolved different names for their two grandmothers. One was called grandma and the other was called grannima.
When I became a grandmother I thought it would be nice to continue this tradition and I would be called grannima and my companion grandmother would be grandma.
But things didn't work as planned, both children insisted on calling us grandma.
In fact, not a lot different to the OP, except I cannot say it bothered me at all, now and again I have a smidgeon of regret, but talk to people and so often it is the children who decide what they want to call their grandparents, not the grandparents.
Favourite small treat when feeling blue or conversely a bit flush
