I Have Family Members That Get On My Nerves

Don't all family members get on your nerves at some point??

I love my grandma a lot, and she helps me soooo much. But she gets on most of my nerves Everytime I see her. She lets her druggie son live with her (who is almost 40.) And she'll notice things going missing.. Money, food, electronics...etc.. Blame it on him, but she'll continue letting him live there. My grandfather is fed up, but she just sits there and defends her son... Like, it's time for him to grow up and realize things.