Grave headstone dispute

[onemoredub]

A bit of a long story, but basically my grandfather has a partner who basically split the family up. My grandfather passed away and he is buried in the partners already paid for grave plot. which we went along with as that is what he wanted. She wanted to arrange the headstone as she "didn't want the family to put any rubbish on it". Now, over 2 years later the headstone is finally in place, but there is absolutely no mention of the family, it just says 'forever in our hearts, 'partner's name' & 'partner's son's name' . She has intentionally left off the family and rubbed our noses in it. Does anyone have any suggestions as to what can be done? Do we have any legal right?

[VillageVicar]

Where do you want the answers? Law or family?