There could be a number of reasons why a female cat keeps barking. Here are some possible reasons:
Hunger or thirst: If a female cat does not have enough food or water, they may bark non-stop.
Mark the territory: The female cat may mark her territory by meowing.
Find a mate: If a female cat is in heat, they may bark incessantly to attract the attention of the male cat.
Anxiety or restlessness: Female cats may bark incessantly due to changes in their environment or feeling uneasy.
Pain or discomfort: If a female cat is unwell or in pain, they may express it through their meows.
Play or socialize: If a female cat wants to play or socialize with other cats, they may bark non-stop. When female cats want to play, they may make high-pitched meows to attract the attention of other cats or owners. They may be jumping around, scratching furniture or cardboard boxes, or looking for some fun toys to play with.
If you notice that your female cat keeps barking, it is recommended that you first check that they have enough food and water, and that they are in heat. If these factors are ruled out, then you may want to take them to the veterinarian to make sure they don't have other health problems.