Stray Cat in labor

Question
My mother has a furrow cat that stays on her back patio that she feeds she has never been able to pet it,it became pregnant around two months ago it started nesting in a laundry basket on top of the dryer this last Thursday and stayed in the basket most of the time this is now Sunday and I can sit quietly out with it last night it left the basket for about three hours and I was pretty sure labor was starting because I notice it washing and moving from spot to spot in several yards it is not getting in the basket once it returned to the patio it sat in my rocking chair so at 4 am I went home thinking it would be today at 7:30 am I got called back the neighbor across the street said they had three kittens between two fences that have been there since Friday problem is this cat still looks as pregnant as she always has and a large part of me thinks they are not hers but I know cats can have their babies as much as a day or more apart but why stay on the porch in a basket nesting to go have the by a fence I guess my question is can they be hers if so why would she keep returning here to nest and wash her area and not look like she had any kittens  if you can help with any advice the kittens have not been touched by human hands I thought if hers I would put in a basket to see she noticed them she turned around and left outside she is back now if they are not hers do you think if I bottle feed the three when she has hers she just might notice I snuck a few extras in lol

Answer
Hi Jean,

Most cats will happily accept foster kittens. This is usually not a problem. The important part is to make sure that these babies don't steal the colostrum, the antibody-rich pre-milk that mom only produces for the first day or so of nursing. If these are not her kittens, this should be reserved for her natural litter. Then, the foster kittens can be added in.

In truth, it may be best to hand-nurse the kittens through until they are able to eat solid foods if you're up for the task. This is because mom is likely to move the babies out of sight for much of the time that they're open to social development (2-5 weeks old). Once this window is missed, the kittens can be very difficult to acclimate to human bonding. They have already received their most important nursing - the first two days.

Best of luck!

Jessica