I'm so sorry you're going through this. Well wishes to you and your girl and I hope for her to get home!
Depending on what treats you've fed your girl in the past, trying calling her name (or any words you've used to indicate treat time. My boys know that if I shake their Puffs container and say "RATS" a certain way, it's food time) and shaking the food container, but quietly as to not alarm her, but so she can hear you. Depending on what she's experienced, she may or may not come out of the hiding place she's discovered. The best way to lure her out is her sister's scent. Get some poo from her sister (or even her own poo), get some soiled bedding, and set it out where you last saw her and surrounding areas. I'd be careful if you bring your other rat outside, even in a secure enclosure. If you need to, stay with her sister, and sit quietly beside her. Don't take her out, just let her sister do her thing in the cage. We don't want to lose two rats.
Ask your neighbors to keep their cats and dogs inside or on leashes until you find your girl, especially if your neighbor's cat did end up discovering your girl. Also, print off and post A LOT of posters with picture of your girl, her name, your name, and your number/email and post those everywhere within the immediate area, and even surrounding area. Get on Facebook, Craigslist, and if you know of any sort of neighborhood app so that your neighbors and the occasional passerby know you're missing a rat.
I know you want to hover around these areas, but she mistake you as a predator and refuse to come out. She's definitely in fight or flight at this point and isn't thinking clearly.
While I'm afraid humane traps could lead to exposure, it may be your best bet for getting her back at some point. Set them out and check them frequently. Find the smelliest treats you have for your girls and put them in these traps.
Also, expect the unexpected. I lost a leopard gecko in my house once and when my grandpa came home, he found her shedding on the middle of the floor, out in the open, but assumed I had lost another one. I tore up the house looking for this little gecko. She appeared three months later, cold but alive. Don't give up hope! Just because you think she didn't go over there doesn't mean she didn't.
i literally slept on the streets and i’m out again tonight. the house i suspect i lost her near has a basement door that is open and the girl said her cat had suddenly been trying to get into the basement the past day so i set up humane traps in her basement. but so far no luck. i’m worried sick i haven’t been able to eat or sleep and i’m starting to fear the worse.
