But why in those circumstances would she say no if asked? And it's not about necessary! It's about something that would be fun for grandparent and child.
As awful as this will sound, and I dont think its pleasant either, often young children do not want to be around older folk, rightly or wrongly.
We rightly took our DD to see great grandma and stayed in her house.
It was awful, horrendous and hideous and GG didnt like it much in the end either.
DD was driven wild with boredom at 4.5. She would not in the end stay in same room as GG, it was excruciating, and she refused to go back.
now older our DD is fine but at 4 aside from telling her off, trying to get her to be polite there was not alot we could do.
so now when GG wants her to stay what do we say? or do we try and protect GG feelings?
Maybe this is what is happening to you op>
Its not always fun children generally like to be with other children.