The computer didn't brought a second queen "from death". It's a complete legal move in chess, if you know the rules, once a pawn reaches the other end of the table ("enemy territory" to say so) he can be switched to any other chess piece (Rook, Bishop, Knight or even a Queen).
The computer won because no matter what move you would have made, he would caught your King with one of the queens, so he Chess mated you!
If you ever reach the "enemy territory" with a pawn, it's always best to change the pawn for a Queen, as it is more powerful!