L.D.
M. ~`
I know the worry, especially with your first, you don't know what to expect! At that age, just before age 1, they do teeth, and eating/drinking and sleeping will change alot also with their growth spurts. My motto was, "just when you figure it out, they change"!
Yes, they need their sleep. At that age I started stretching the 3 hour window, but basically, WHENEVER they get up, they have 2 - 3 hours awake time, and then put them down for a nap (AS SOON AS YOU SEE THEIR SLEEPY SIGN)...with the same short (15-20 min) routine, try not to do it right after they eat! (a full tummy can be uncomfortable for sleeping). This was my major problem with my little guy so I became an expert...at least for me.
As for food, if she's getting some solids plus milk, she should be fine unless she really starts losing weight. (My little guy also wanted some pure water at that age). Trust your "mommy gut" if she starts acting sick or really not herself. As folks told me, you'll have to roll with the changes. Good luck and enjoy the process. God bless.