I am so sorry for both you and your SIL and I really understand both your points of view.
Could you afford to pay a gardener or groundsman at the cemetary to keep your daughter's grave looking nice?
Or could you and your SIL agree that you put down a layer of gravel and plant a shrub or two, so that the grave does not look utterly neglected until he can face going there - if indeed he ever can? An evergreen of some kind and either paving or gravel will make the site look more cared for.
If none of these suggestions work for you, try to accept that your daughter's ashes are where she wanted them to be, and if you have a garden or a small courtyard plant some of her favourite flowers there and make it a memorial corner to her.
If you don't have a suitable outdoor area of your own, go to a park or woodland area near your home and find a tree or bush you like and call it "hers" in your mind.
Jersey trip, some tips please.
Will Replacing School Uniforms With Tracksuits......



