Check whether the cat is stray or feral
After looking at the cat outdoors, you need to find out whether the cat is strayed or feral or truly wild. Usually feral cats do not trust humans e.g. if you are feeding a cat for many days and when you try to approach her, she will run away. This is also one of the reasons they are able to survive in wild. These cats do not socialize easily. However, trapping, neutering and send it back from where it came is one of the good deeds you can do for her. Do keep in mind that these cats can talk to you and befriends with you. You can even pet it. For stray cats, you can simply trap them and return to its owner or find a good home.
Call local animal control agency
Usually people call animal control agency when they see feral cats. However, the best thing to do is to trap, neuter and release the cats so they can live their natural lives. You can find out whether a cat is neutered by looking at her ear. A small tick or clip of hair is taken from their ears if they are neutered.
Contact local feral cat organisation
Instead of tackling a feral cat alone, you can contact your local feral cat organisation. Visit alleycat.org and find nearby feral cat organisations. These organisations will not only provide you a trap but will also give suggestions of trapping her. They will also lead you properly for how to provide a shelter for the feral cat, how to neuter and how to take care of her.