I feed wet food 4 times a day. My kitten's 5 months now, and she eats about 40 to 50 grams each time. She gets a small bit of milk with each meal. On top of that, there is a bowl of dry food for her to nibble at throughout the day. As far as the wet meals are concerned, she might not quite finish her meal each time, but she does get back to it later. Next time I need to feed her the bowl is practically empty (a few bits might remain). I have tried to increase the amount to about 60 grams, because I think she eats very little, but apparently about 50 grams are enough for her. It's been that way since I got her. There's been only one time (she'd been in the garden chasing butterflies all day and got a lot of activity) that she ate her bowl, stayed in front of it and looked up at me. I added a bit. She did the same thing all over again. I refilled a few times, and she ate 100 grams in one go! That's how I know she needs more food.
She'll sit there until I fill the bowl again
She never meows for food, but is very happy when she gets it, which makes it hard to guess at what she needs. I do keep a close eye on her, and stay around while she's eating.
The first type of wet food I bought stated the amount to feed was about 50 to 60 grams a meal, and no matter what food I give her, 40 to 50 grams is still her limit. The wet food, I measure. The dry food, I don't. She gets a good handfull, and never finishes it completely.
Measuring the food you give her, and weighing what she doesn't eat will give you an idea of how much to feed her. Add a bit more sometimes to see if she doesn't want more.