My aunt runs a sketchy daycare, am I right to warn people off?

Ok so I DON'T talk to my aunt, she runs a daycare and NOT that great of a sitter! My friend helps her and tells me things all the time....

So my friend called me last Monday and told me my aunt took a butcher knife after a 4 year old because she was jumping on her precious couch! She told her if she doesn’t stop jumping she will cut her goddamn legs off! She was actually carrying the child in her arms and had the knife to that 4 year olds leg! Fast forward to last Wednesday, 2 kids were picking at her wall… Both babies are only 1 year old, she told them if you don’t stop picking at my walls she is going to cut their fingers off!

Well one of the parents at the school my kids go to school with is looking for a sitter. I private messaged him and told him NOT to take his son there because my aunt is not a good sitter. I even told him what she’s done and who the other parent was. Well the parent I told that to sent it to the parent of the child that got the knife taken after. When she was picking up her daughter, she showed my aunt what I said! So after the parent leaves my aunt has the nerve to call me, saying “why do you always have to cause problems for me? Why do I hate her so much!” Well for one I was giving the parent a heads up! I was NOT trying to start trouble I was simply looking after the child’s safety! The parent said that she DOESN’T believe that my aunt would ever do that! Which I know her better then her daycare parents…

So I have 2 questions…

Question 1: Was I in the right for giving other parent a heads-up?
Question 2: Would you as a parent look into it when you were told your child got a knife pulled on her or would you believe your sitter?!