Instructions
File a report with the local animal control to make sure the cat does not belong to somebody else. Put up some flyers in the neighborhood. Many times, house cats escape when a maid leaves the front door open or if there is furniture being brought in or out. It's possible someone is looking her.
Bring the cat to a veterinarian as soon as possible.If money is an issue, bring the cat to a local shelter or animal control. You need to have the cat checked for communicable diseases as well as internal and external parasites. The vet will counsel you on whether the cat has been spayed or neutered. You will want to have that done to prevent more unwanted litters. Call your shelter or cat rescue group to find a low-cost vet clinic. It is possible to get this surgery done inexpensively in most places, you just have to call around.
Go shopping. You will need to purchase cat supplies such as a litter box, scooper, litter, food and water bowls, cat food (wet and dry), treats and toys. Your cat will most likely want to sleep with you and be around you as much as possible if she is a social cat, so get used to having a cat in your life and congratulations for joining the ranks of cat people.
How to Care For a Stray Cat
It's hard to ignore stray cats, especially when they show up hungry on your front porch. If a stray is friendly, chances are she used to have a home and is either lost or has been put out to fend for herself. Truly feral (wild) cats are very shy and may never show themselves. Your choices range from ignoring her--she will leave once she realizes she won't get fed--to taking her inside as a pet house cat. Hopefully, you have decided on the latter.