- It is possible that you will need to change terminals, as I think TAM operates flights from both.
- As Eastbay1K said, you will need to pass through Policia Federal's border control.
- After that, there is a corridor connecting the two terminals (airside). All lounges are situated in this corridor
- GRU is not a very large airport, but depending on the specific gates used, there could be some moderate walking involved. With only 1:30h between flights, two kids, border control (highly variable in time taken), expect a short lounge stay.