I live about 4 hours drive from my baby DD's grave. She died at birth 14 years ago. We used to live in the area she's buried in but had to move for work about 8 years ago. We make a trip down there every year at around the time of her birth/death to visit her grave and tidy it up with our other 4 DC as a way of keeping her integrated into our family.
My mother used to live in the area as well (not for the past 5 years) and always made a point of tending her grave, sending me texts with pictures of what she had done, which was not well received I have to say as these pictures would just pop up at random times and I used to find it upsetting and told her so but she could not understand why! She also completely took over the funeral, choosing the flowers, insisting a priest came and spouted from the bible about god's mysterious way etc causing me enormous upset and my then 4 year old DD still remembers the argument she had with me about it, chose the burial plot which I did not want as it's right next to a turning area of the road and the headstone has been damaged by reversing cars, and even put the burial plot in my stepfather's name so I have no 'ownership' over it anyway! DH and I were an utter mess in the aftermath of DD's birth and DH had never arranged a funeral anyway, so at the time it was all a blur.
We have now been NC for almost 2 years due to various issues which arose when I confronted her about my abusive childhood. She cut me off and at the time I told her that she shouldn't bother contacting my DC until she had worked out the issues I had with me. I was then told in a long email how much hurt I had caused her depriving her of her grandchildren and how when they reach their milestones and she's not there, I had only myself to blame. I later relented a few months later due to guilt and sent her an email telling her I would enable a relationship between her and my DC, without me being involved (don't quite know how I would do that when she insisted she would never speak to me again!) but she never responded and that was a year ago. DD also sent Christmas cards to my whole family (everybody has cut me out at this point out of loyalty to mother), and she also never responded to DD even though DD gave her personal mobile number for her to contact her on.
Anyway last year we noticed someone had dug all over the plot and planted flowers there and I was a bit perturbed as to why my mother (I know it was her) had done this as she insisted I was not part of the family and she was not bothered about contact with her living grandchildren who she had a relationship with for 16 years 
.
Today, we have been again, expecting the grave to be very overgrown with plans to weed, plant and scrub the headstone and find it all done. Flowers I had not chosen all over the grave, not a weed in sight, headstone like new. My mother has basically taken ownership of my daughter's grave. I wanted to do it, not her. I did think of ripping all the flowers out and planting my own but couldn't bring myself to disturb it.
AIBU to wonder what point she is trying to make and to be bloody furious about it?