I want to sleep with my grandma
What made you feel the need to do that?
She pays a lot of attention to me.
Do not act upon these urges. It is wrong to sleep with your family members in that way, and it is even illegal in some states.
Sorry, I just meant that I like her.
Perhaps I badly misunderstood what you meant, but regardless of what your intentions were, when you say "sleep with", that tends to mean physical intimacy.  If I understand correctly, you want to sleep next to your grandmother to keep her company, but even that is going overboard.  You can choose to live with her, so she will not be lonely, but respect her privacy after dark.