Ok: I have been involved in kitten birth twice in my life 25 years ago. First thing: if they kick etc. that must not be contractions. In the late time if you watch closely and hold your hand on them you can nearly count them, they are so big and each of them acts different.

When Grisette had her babies the first time we didn't recognize the signals. We had a box but she went out in the evening (she was indoor/outdoor) and I woke up in the night thinking I heard a mew. Went on the street looking for her. No Grisette.

The other morning I opened my closet and there she was, on the bottom, on some old clothes with 4 of the sweetest little kittens, all little tigers. She had managed purrfectly well to deliver them and all was clean and cosy

Unfortunately she got pregnant very shortly after (while she was still nourishing the first ones, we didn't dare to take her away for spaying - we thought she couldn't be pregnant while the other kittens were that small). Ok, the second time she allowed us to watch and had them in the box. It was so great. I still feel honored. She purred while she gave birth - everything was very fine. (All of these kittens got good homes, together with a litter I found at the same time in the woods)

So there is a high probability that Sada will do fine. All the best for her and you!