Depends on your budget, and on your priority for gaming...
If looking for a laptop to work, and play a few basic games (leaving out Doom3, HL2, FEAR), there are nice Athlon 64/3500+ laptops by HP avail for sometimes right at $1000...; this one is a Toshiba with a Celeron-M, and does quite nicely at everything but high res gaming, but at 800x600x16, its even useable for the first COD game, old Quake3, etc.....
If playing FEAR and/or Doom3 on a laptp is vitally important, and there will not be an accompanying desktop for gaming, best look at Alienware or Dell 17" laptops equipped with either 6800U/7800Go integrated video....but they quickly push $2700 and up...
Which route you choose, is a matter of your conscience, and your mother's budget and generosity...