Is this ammeter and power reading correct?
Should I calculate the power as 25ohm and 12V to get a power loss of
5.76W? Since the Current would be flowing through the resistor. The ammeter will then read 2-0.48A which is 1.52A.

Because the ammeter's internal impedance can be assumed to be zero, there has to be 12 volts across the 25 ohm resistor. That means the power in the 25 ohm resistor is: -
$$\dfrac{12^2}{25} = 5.76\hspace{0.2cm}\text{watts}$$
And the current into the resistor is \$\dfrac{12}{25}\$ amps = 0.48 amps.
The rest of the current from the 2 amp source flows into the 12 volt source via the ammeter i.e. 1.52 amps.