Last summer when we mover into our house a cat adopted us. She is pregnant and she went into labor 10 hours ago. In the first hour she had 2 live births. She is behaving quite normally, she gets up and walks around and is eating. She is not nervous or panicky, she is purring. She wants her belly rubbed all the time and wants to be near me. I am certain there are other kittens. How long is too long for delivery? Is there anything I can do to speed up the process or should I be concerned?

Thank you in advance for any information/advice you can provide:confused!