Hello /an/. I'm wondering if you guys could give me your input.

There's a stray cat who lurks my part of the apartment complex I live in. I call her Mika. She's very sweet and affectionate and walks right up to you, so I think at some point someone must've owned her. Anyway, with Halloween drawing near, I'm a little worried about her safety. I don't know how many sickos live around here but I don't want to take any chances. I don't live in the safest neighborhood. Sure, there are small children who live here and we're near a hospital and a school and all that but just a block away is a total shit hole. We have a lot of cats who wander this place and I'm afraid that someone might come and hurt them.

I don't feed Mika. She just kinda drinks the water that drips out of an outdoor faucet. She's pretty fearless of people, so she would be an easy target. She doesn't even run away if you run at her.

How can I help prevent her from getting harmed during Halloween? Maybe I'm just overreacting and there's nothing to worry about, but I wanna make sure just in case. I can't take her in because me and everyone I live with is allergic. There isn't anyone I know who could take her either - I've asked all my friends and they're either allergic or don't have the money/space. I was thinking of putting a collar on her on Halloween day, just to MAYBE increase her chances of being spared. Like maybe someone will go "oh how about that one? Oh wait. Nah that one belongs to someone. We should stick to strays." ? Sounds stupid now that I read it over, but would it work? Even a little bit? Or should I just put up with my allergies and possibly get evicted (can't just sneak a random pet into an apartment without some risk) just to stow her away for a night or two?

>tl;dr
How can I help a certain stray cat from being possibly hurt during Halloween?