Yes, little babies sleep all the time. If you look at the link you'll see that from 1-3 months old they sleep anywhere from 15-18 hours! If they sleep on the long end of that, that's only 6 hours a day that they are awake!!! It used to take my girls about 45-60 minutes to finish eating, so you can imagine, their "A" time was spent eating, plus they used a lot of calories eating.
A crib party is when they wake - usually in the middle of the night, but can be during a nap - and they babble and coo to themselves. Hopefully at this point, when your LO is waking, you are not rushing into her. You are giving her a chance to wake up and get her bearings and then you go in and greet her. Sometimes crib parties can last up to an hour. It's really hard in the middle of the night to listen to b/c you're kind of waiting for the other shoe to drop - thinking she is eventually going to start crying. But if you have a good foundation of not rushing in as soon as she wakes up, she will usually fall back asleep. It's no big deal, and you shouldn't make a big deal out of them. It's actually great b/c it means she feels comfortable in her crib and it means that she can put herself back to sleep - two very important things you want her to be able to do!
Also, I would say, enjoy it now. Many LOs sleep goes crazy between 4-6 months. It's not necessarily going to happen to you. But sometimes they stop being able to take long naps, and they start to have NWing or EWings when they previously didn't. It has to do with them being able to stay awake for longer periods of time, and getting the A time correct. It's a developmental thing. So, I'm not trying to get ahead of you, I'm just mentioning it! One of my girls had NO problem when she hit the 4-6 month bananas thing. My other girl did - and we had short naps and NWings. Depends on the LO! Sleep when they sleep. I didn't do this and paid for it. Talk about OT!. As suevcameron says - it's nice for you to feel rested too. It helps with your confidence level and helps you deal with anything that might come up.
I agree with suevcameron! You're doing a fab job!
Lu