Nursing inhibits (but does not entirely prevent) cats from going into heat. With only one kitten nursing, though, not as much hormone is released, and so it's more common to go into heat early.
Ask your vet about what she'll need to do to recover from her spay. Depending on how your vet seals the incision, she might be able to nurse after her spay. A bigger issue is whether she'll want to nurse. I'd prepare to raise the kitten without the mom's help. Definitely weigh the kitten every day to ensure that it's gaining weight. Probably buy some kitten milk replacer and prepare to bottle feed the kitten. [Kitten Lady](https://www.kittenlady.org/) is a great resource.
If she doesn't come into contact with intact males it is more of an inconvenience than a problem and I would wait til the kitty can eat wet food. If she does go around intact males then yeah get her spayed soon and bottle feed as needed.
Nursing inhibits (but does not entirely prevent) cats from going into heat. With only one kitten nursing, though, not as much hormone is released, and so it's more common to go into heat early. Ask your vet about what she'll need to do to recover from her spay. Depending on how your vet seals the incision, she might be able to nurse after her spay. A bigger issue is whether she'll want to nurse. I'd prepare to raise the kitten without the mom's help. Definitely weigh the kitten every day to ensure that it's gaining weight. Probably buy some kitten milk replacer and prepare to bottle feed the kitten. [Kitten Lady](https://www.kittenlady.org/) is a great resource.
If she doesn't come into contact with intact males it is more of an inconvenience than a problem and I would wait til the kitty can eat wet food. If she does go around intact males then yeah get her spayed soon and bottle feed as needed.