First of all , welcome to our Pettalk-family !! It is a lovely place to be !!!

Don't worry if your cat eats less than other cats . Remember that a cat always knows how much she (or he) needs ; it will also NEVER over-eat !! So , if your sweetheart looks healthy , is active , and acts like a happy cat , there is NO need to worry !
If you are not sure , you can always ask your vet .
Success !!