My first question... is she house trained already? Does she have any accidents?

Second question... How long has she been sleeping with you? From what age?

Third question... What do you do when she steps on your head and doesn't let you get any sleep?

I believe a 3 month old puppy should not be sleeping in the bed with you no matter how much you want it. You need to establish that you are the alpha over the pup and one of the best ways to do this is to let pup know the bed is yours. Now with that being said, I also let my pups sleep in bed with me but..... and it's a big BUT.... never until they have completed a puppy kindergarten class and are completely house trained. Usually this happens around 4 to 5 months of age depending on the pup. The puppy class helps them to understand you are the boss too but also gives them the socialization they need with other dogs. This is very crucial at this point in their young lives.

I use the crate until they understand that being in the bed is a priviledge and not a right! I do however put the crate in my room so the pup can be near me. Dogs are very social animals and most do not like to be isolated from their owners.