The early window is real, and it closes
Kittens pass through an early period when new flavours and textures are accepted with an openness most adult cats never show again. What a kitten eats in those first months helps set the template her adult brain files under 'food' — which is why cats raised on a single kibble can become the adults who starve themselves in protest when that one food changes recipe, goes out of stock, or must be replaced for health reasons.
Using the window does not mean feeding her everything. It means deliberately widening the template while widening is easy.
The base-and-rotation pattern
Keep one complete kitten food as her constant base — the food most of her meals come from, the one her stomach knows best. Around that base, rotate a small supporting cast: another protein in the same kitten range, the same protein in the other format. A kitten who knows chicken as both wet food and kibble, and who has also met fish and turkey as kittens' foods, has learned two lessons at once — that protein varies, and that texture varies — and those two lessons between them cover most of the changes adult life will ever ask of her.
Introduce each new food the gradual way, mixed into the familiar over a few days, even in this adventurous season. Variety is about range, not speed: a new food arriving abruptly and causing an upset teaches her the opposite lesson, that novelty makes her feel ill.
Pace and proportion
Rotate at the pace of weeks, not days. A different food at every meal is not variety, it is instability — her stomach never settles, you cannot tell which food caused a loose stool, and mealtimes become unpredictable for an animal who thrives on pattern. Keep the extras as proper complete kitten foods rather than scraps from your own plate; table food teaches begging and an unbalanced palate at the same time, which is the one kind of 'variety' that creates problems instead of preventing them.
Offer the rotation in her normal bowl, at normal mealtimes, without ceremony. If she declines a new food, do not chase her with three alternatives in one sitting — that is the first lesson in training owners, and kittens learn it fast. Simply return to the base and try that food again another week.
Watching what the experiment tells you
Note, even roughly, which proteins and formats she took to readily, which she tolerated, and which reliably disagreed with her. That record becomes genuinely valuable later: the adult cat who needs a diet change for health reasons is far easier to feed when her owner already knows two or three proven foods she accepts. Note also any food that repeatedly produces loose stools or vomiting and drop it from the rotation — openness has limits, and an individual kitten's digestion outranks the theory.
If she refuses food altogether for more than a day at any point, or the variety programme keeps producing upsets despite gradual introductions, talk it through with your vet, who can check that nothing physical is making eating difficult.
A record of her range, kept from the start
Memory blurs which food she loved in March by the time she is an adult. KinsLe Care Teams lets you log each new food against her feeds as you introduce it, building a timestamped record of her accepted range — so the variety you built in kittenhood stays available to whoever feeds her for years.