A gift for a deceased family member???????

Every 2 weeks my mother and I go to a small cemetary where her parents are laid to rest. We clean up the area around their headstones and plant new flowers and water the ones already planted. This helps my mother in her time of grief. Every Christmas my mother puts out the small Christmas tree that lights up at night...(my Grandmother loved Christmas). I always find something small to put at their gravesite... maybe because I am always use to them being their at Christmas and I have always given them small trinkets. I have given sea shells that I found at the beach one year and projects my kids worked on at school but this year I am at a loss. I think it is because I am moving on.... even though losing them both in the last few years has hurt me terribly. I am wanting to do something different this year. Maybe donate to the Cancer Society... Maybe pay more tribute to them that way???? This is a very touchy subject and I would like only serious suggestions here. Please be kind and leave an honest suggestion...