I am confused? On May 30th of this year you said she was only 9 months:
Wouldn't that make her 11.5 to 12 months old currently?
2.4 lbs is awfully small, I'm sure you're rolling your eyes at the computer screen right now and ignoring what everyone is saying, but seriously you could have lost your little girl very easily. 2.4 lbs is really too small EVEN for a pet, let alone a breeding female. I also have a spayed 3 lber and she is so fragile and just tiny overall. I would have never considered breeding her, I love her too much to risk losing her over a couple of puppies. It was not worth it to me.
Also if she is that upset about being a mother she is better off being spayed anyways. There's a good chance she will be the same way if you bred her again, and next time she may need a c-section and you will be out even more money for vet bills and probably lose one or more pups as well. I finally bred one of my 5 lb girls on her 2nd heat at 2 years old this spring. She had one surviving pup and she was scared to death of him at first and I finally got her to calm down enough to let him nurse, and she cleaned him and went to sleep. I was laying on the couch beside her and I closed my eyes for a few minutes. I was startled awake by her shaking him in her mouth. I quickly got him out and worked on him, but it was too late. It wasn't her fault, it was mine. As soon as mom's milk dried up I had her spayed. She is now in a pet home and doing absolutely wonderful. I did not want to put her through that experience again. Some females, even those who are the right age and size, are just not cut out to be mothers.
I hope you will really think about all this and not just ignore what is being said. Please listen to your little girl and look at how much stress she is under. Is it worth it for her to have to go through it again?