Not really, the death was just at a fine pace...I don't really see how it should be extended. The camera zooms out, the tail settles, and the mother dies. I personally feel there shouldn't be any dialogue at all except the mother's directions to the great valley (since it was significant to Littlefoot).
For the sharptooth...remember, he was all screwed up in the head after his post-tragic situation. He really couldn't think. Of course, when I was younger, I asked, "Why is Littlefoot blaming his mother?" I'm older now I fully understand why.