I'm sorry to hear of your loss, this is a beautiful memorial,the plants and vessels.
When my dad passed on we recieved a dracena,with 3 large stalks,over the 5 years it's grown so well and strong, I made more plants this summer from cuttings.
I think trees,plants and/or houseplants are wonderful ways to remember our loved ones.
Your grandmother is very proud to see what you are doing, though you may not see her, she's with you, always . . .