Enrique, my condolences for the loss of your Grandmother.
Welcome to the forum.
I don't know if a family member contributing to the eulogy of their loved one is not permitted as LongHairGal suggested, but in almost 40 years as a JW, I've never seen that done at a Kingdom Hall.
All JW 'memorial' services I have attended, have been as LHG mentioned, mostly a presentation about the beliefs of the departed person, with only minimal mention of the person they claim to be memoralizing.