AITA for telling my grandma's sister she should stop caring about our family and take a look at her daughters?

I (17M) live with my mum (49f) my dad (50m) my grandma (79f) and little sis (14f). Since my mum and dad work all day grandma has decided to do the chores while me and my sis are at school. This has been going on for years. Last couple of months I've noticed she's getting a bit tired so I finish chores after school so she can sleep a bit. That fatigue is often shown in various arguments with my mum. Grandma often takes advice from her sister (83F) who has 2 daughters let's call them Jenny (53f) and Megan (46f) which tells her to dump as and leave for the village to live with her and her daughters. My dad always says that grandma's sister and her daughters are the worst part of our family tree and honestly I agree they are spoiled and really bad people that have done some immoral things to other members of their family. During a family table my grandma moaned a bit about having to cook all alone when mum had her day off and was sleeping until noon. Then her sister said "I told you to leave those ungrateful bastards they don't appreciate what you've done for them unilke my daughters who are an example of children raised right" in this moment I couldn't hold my anger I stood up looked her dead in the eye and told her "Are you really saying this? For your information we are all grateful of her presence not only because she does the chores but because she grew up my mum, me and my sibling with values and morals unlike you and your daughters. Have you wondered why Jenny got divorced twice or why Megan cant even find a job. You didn't do as good of a job as you think raising your daughters. You have no right to call us like that in our house in our table". Dad told me to go to my room so i left. I overheard my grandma's sister saying I wasn't raised right but my parents defended me. After she left dad said I was right and apologized for not interrupting earlier while mum said I shouldn't have done this. I do think i did the right thing defending my family and putting her in her place. What do yall think?