As soon as possible from four months old. Definitely before the first season some time after six months old, unless you wish her to have kittens. Cost depends on weight. Spay three months after first or any following season. There are marked health benefits in not leaving it over two years.
Cost depends on weight.
You will normally be advised at an earlier consultation if this is neccessary. If not, please book an appointment for that morning's surgery for a check first. This will normally result from an earlier consultation, or be performed as an emergency, so the details will vary from case to case. .