I have a question about my cat?

I recently adopted a beautiful 2 year old Maine Coon cat from the Humane Society. It's my first pet in probably 4 years and my first cat since I was a teenager. I feel like an overprotective "mom". But I am worried about her. I've noticed she hasn't been drinking her water these last couple days. I mean sure maybe she is when I'm not looking. But I'm with her nearly all day. She hangs out on my sun porch a lot, sleeping in the sun. I'm worried that she'll dehydrate. So far she seems like her normal silly and playful self. She's still eating, playing and running around. But I don't see her drinking and she seems to be urinating less. I've not scooped as much out of her litter box. Am I right to be worried or am I making too much of this?