Try having more protein, a spoon of coconut oil in the morning and before bed.. and have cheeses and yogurts it will increase the fat in your milk but watery milk is also normal it honestly just depends on your diet
This sounds like foremilk. If you pump longer, does it go more yellow/milky? Do you feel “empty” after you pump? You should always start each feed/pump with foremilk which is meant to hydrate baby then it’ll transition into hindmilk where the fat is. If you find you are not getting to the hindmilk while pumping, try doing breast massage and compressions before and during your pump
Your milk changes consistency throughout the day depending on baby’s needs. So if baby has had most of their nutrition the milk fat levels will change and it will be more watery for hydration. If they need more of a meal it will be higher in fat etc. it’s very clever but it will be why sometimes it appears more watery. It won’t be that consistently all the time 😊
how many weeks pp are you?