That is a point Dr Who is 900 an odd and Captain Jack is over one hundred. Got it she isn't the main protagonist but Estelle - Jack's love interest in the Fairies episode of Torchwood.
How about Pixar's "Up"? The main guy is about 800 years old and has a walker with tennis balls on it. And that movie was predominately targeted at kids. What did they do? They threw in a kid as sidekick. Simple and beautiful.
^All of that. No one cares how old your protagonist is, so long as whatever they're doing isn't totally outlandish for the genre/audience, and that they're human enough to connect with. It's that humanity that'll bind the reader to your protagonist, and make them feel anything and everything for them. Also, someone mentioned it earlier in the thread, but humor is a great tool for connection and audience interaction. If you want to keep the protagonist simple and mostly humor free, throw in some funny or witty characters around them to keep things humorous and alive. Just a thought.
There's Betty White's character in "Lake Placid". IMHO, she stole the show there. If you consider disaster films as a type of horror, Shelley Winters in "Poseidon Adventure". (RIP Leslie Nielsen) -Frank
Disclaimer: I haven't read the whole thread, just your main question, so I apologize if this has been said about a hundred times: I don't think the age matters as much as whether you can successfully create a character who is in her 60s. Personally, I am only 19, so I would have trouble writing a realistic character at that age. But I know it can be done, because there are plenty of precedents, including Miss Marple from Agatha Cristie. Like any character, if she is well-developed, her motives are understandable, and she is portrayed well, the audience will sympathize. Because if we can sympathize with a Nazi in the book Mother Night, we can sympathize with an old lady!
Maybe it's just me, but old women and dogs always get my sympathy. As for old ladies in the horror genre, (where their current role is generally to be as creepy as possible) I love the idea of Bunny being the protagonist. And you are not wrong making her 60+, it's already a horror sub-genre psycho-biddies. (And one of my favorites.) Please watch "Lady in a Cage" and "Whatever Happened to Baby Jane." All you need to make us care about Bunny is the tension and the suspense. Even if she's a cranky old woman, we'll still want to see her live. In fact, her age is an amazing tool, because instead of her being dumb enough to lose her cell phone--she doesn't have one. Instead of her being dumb for not running away--she can't run very fast. Instead of her being too dumb to just fight back--she can't because she's too feeble. She's arthritic. Stairs are her mortal enemy. She doesn't have her youth or her beauty, she only has her wits.
