Transitioning to wet food

Hi! so my cat is 7 years old, and we've been free feeding her this entire time, with only dry food. I've been trying to get her on a routine so that the transition is easier, and i've been providing both dry food and wet food. I've seen her sometimes ignore the dry food and eat the wet food, and at times she eats the dry food and ignores the wet food. I leave the wet food for two hours before throwing it out since i heard that it builds bacteria and can be harmful if left out for too long, and since i end up throwing the dry food as well since its sitting next to the wet food so it might also build bacteria (same bowl), perhaps separating them would be better so i don't end up wasting the dry food? During these two hours she eats a few bites and never returns. Since im trying to transition her into a routine rather than free-feeding, how often should i leave the dry food out for? I've tried feeding her three times a day but usually mid-day she's not even interested in the food, so i've been doing it once in the morning and once in the evening but regardless she's eating little, even the dry food that she usally eats she ignores. Im gonna try out different brands that are also good for her in hopes she'll be interested, but in the mean time, how long should i leave the dry food out? I don't know how to balance it, cause im worried that if i leave it out too little that she goes hungry, and if i leave it out too much then maybe its too similar to free feeding if that makes any sense? I hope i explained this well, english isnt my first language so please bare with me! I appreciate any advice and thank you for reading! :)