Uncle Edwards told her son that he should wait until later and playing flag football would get him plenty of experience and probably even develop better skills and habits than starting tackle at a younger age.
The parents wanted to wait and the kid wanted to play tackle because his friends were. Lavell sided with the parents (which may have influenced his answer). But he told the kid that there is such a huge difference in size and strength at his age, that a lot of kids learn bad tackling technique due to just trying to get the other guy down. And that it would benefit him to wait until he was a little older.