If you are not prepared to be responsible for an animal for its entire lifetime, then you should not adopt that animal. For a cat, you should anticipate a minimum commitment of 15 years, and potentially over 20 years of responsibility. You will need to provide for food, litter, vaccinations, medical care in case of accident and injury, and end of life care during that time. You will also need to provide enrichment in the form of toys, scratching posts, and cat furniture, in addition to basic needs like bowls for food and water and a litter box. And you may find that what you bought doesn't suit your cat. You bought a small litter box, but she's a larger cat and needs more room. You bought jingle ball toys, but she prefers stuffed mice.
You have made this cat dependent on humans for survival. If she is left as a stray, she will likely die. If you're unable to care for her, you should contact a local rescue (if available) or find someone who would be able to take responsibility (evaluate them to ensure they will not harm the kitten). The lives of stray cats are typically short, with violent ends; even without her dependence on humans, she'll still have a better life if she's kept as an indoor cat. You should take responsibility, at a minimum, for ensuring she will have as good a shot at a good life as possible, as the one who made her dependent on humans.
Cats will generally self-litter train. They are naturally inclined to hide their waste; you can start out with a cat-attracting litter or litter additive to ensure she uses the box early on if you choose to adopt her. As long as she knows where the box is, she should have no issue quickly learning to use it.
Cats do not have "families" the way humans do. There is no reason to not desex an adopted cat, and failure to do so will result in the cat roaming (possibly never returning due to being adopted by someone else or being killed while out seeking a mate), as well as even more homeless cats that will live short lives with violent ends (and that will, during those lives, have a negative impact on local wildlife such as birds). If you decide to take responsibility for her, you should absolutely have her spayed, and keep her indoors.
Former strays can make fantastic housecats; one of my current three was a rescued street kitten who has adapted extremely well to living in the house, and who now will never have to struggle to find food or shelter or be at risk of being killed by a car, another animal, or a cruel human. By feeding a stray, you only remove one of those struggles for them, but the rest remain. By finding that cat a home indoors, whether your own or that of someone you trust, you can remove all those struggles as well as protecting your local wildlife and helping to reduce the overpopulation problem with stray cats.
If you choose to take her on yourself, remember that pet ownership is a give-and-take relationship. You will have to make adjustments to your lifestyle, and she'll have to adjust as well. Like any relationship, you can't expect one party to make all the concessions; if she wants to sit on top of furniture, give her places to sit. If she wants to chew cords, put them away. But if she wants to wake you up at 5 am, train her not to do that. Understand where to compromise with her, and you'll not only help her have a better life, but you'll find your own enriched by her companionship.
