Healthy Feral Calico Showed up and decided to live here?

Hi! First post but didnt know where else to really turn. so i have a half outdoor, half indoor cat (i live in the country and out here there are a LOT of barn cats its relatively safe for them to be outside) and he is great! i meow for him, and if he's up to it he comes home. i more of just do it to let him kno wwhile he's out there that "hey, im home; if you want food come!"

well, the other night i meowed after getting off work and went to game. like an hoour into gaming; i heard a "MEOW" that sounded half human half cat. i thought i was trippin; so i went outside and meowed once likei normally do then once how i heard "MaowWW" and then...i saw a random calico pop its head out of the grass? it ran up to me; it looked T ERRIFIED; and was very skittish but it was half "do i?" half "no it will hurt me!" going back and forth fgrom the grass then closer to me, i grabbed food and sh ook the dish offering it and it walked up and kept walking to the grass then up to me; eventually eatin out of the bowl of food when i was holding it; i sat the bowl down and shut the door and thought of what to do.

well, i got it its own bowl of food and when opening the door for that it just decided to let itself in; it hung out for a bit inside grabbed food and water and left; then came back later and was at the door againg wanting in; so i let it in and try to pet it; and it after like 2 hours of cautiously leaving and coming back and half scared half not; it let me pet her..

its been about a week now; every day i get off work and she's outside my door wairing for me. she stays and doesnt want to leave; ive used my shampoo on her and i need to take her to a vet still but i think my tomcat already hto her pregnant; other than that she seems healthy by all metrics. she's caught 3x the amount of mice the cat that i got to..c.atch mice catches; but kinda looing for a little advice?

nobody in the area reckognizes her or is missing a cat; she looks ot be about a month or two months old and gijven the amount of strays that live in the woods (they are sparsley seen; though we know they are there. one showed up in my garage 2 years ago, had a litter- then dipped forever to never be seen again) so im assuming this kitten is just one of the strays' kittens that grew up and said "screw outdoors!" or what; but she was SKINNY whens he came in; rough fur and like i said she was...she looke dTERRIFIED. whatever or whoever she was running from; she was scared. she acts skittish occassionally; but ive found her waking up curled up right against me the nights shes been inside when ive fallen asleep...

1- how do i go about chgecking if shes chipped isnce nobody reckgonizes her?

2- would it be better to rehome the kitten; given i have a tom- or spade her? She seems to like it here a lot; i wouldnt mind a second cat; im just worried about dealing with kitten litters every year...id have to find new homes every year if i didnt spay her either...

3- now that i know shes out there; any recommendatins on making a little habitat in trhe forest for her? given its where she came from; there's probably other cats out there and my cat goes outside too...i'd hate for there to be starving cats in the wilderness and i just cant find them im worried if she has sibligns?