What would happen if I report my grandma to 016?

First of all, English is not my first language, so I'm sorry if there are any mistakes.

Location: Spain, As the title says, my grandma, 86F, is hitting my grandpa, 90M.

This is a complex situation, so please bear with me. My grandpa has suffered dementia from a few years, previous than COVID-19. First he developed Alzheimer, and it got worse when he suffered an ictus that led him with half of his body unresponsible. Now he suffers occasionally epilepsya. The thing is, he can't communicate at all, he can only scream. My grandma is taking care of him 24/7, and even if she has social assistance 6 days a week, it's still a huge mental stress for her.

My aunts are the main caretakers of them, and they DO know that she hits him. But they're lying to the doctors and social workers saying that he scratches his eye a lot to the point he makes his eye bleed... Yeah. Well.

So, the thing is, I could call 016 and report this, but my grandma would face legal punishment. She's 86 yo, she's in a bad mental state, slowly developing dementia. I've been trying FOR YEARS to get her mental help, but my aunts are denying it everytime, and they don't even consider me a "proper adult" (family drama) so my suggestions are always ignored. My cousin, one of my aunt's daughters, is a neuropsycologyst, and she agrees with the mental help, along with my uncle. But theyw on't listen.

What would happen to my grandma if I call 016?