Arduino and 2 Adafruit Fingerprint modules working together
Yes, you can easily do that. This finger Print sensor works over Serial communication. 

You can have multiple Serial devices connected to your Arduino UNO using SoftwareSerial library.

All you have to do is to create multiple instances of Adafruit_Fingerprint initialized with different SoftwareSerial objects. i.e.

// pin #2 is IN from sensor1 (GREEN wire)
// pin #3 is OUT from arduino to sensor1  (WHITE wire)
// pin #8 is IN from sensor2 (GREEN wire)
// pin #9 is OUT from arduino to sensor2  (WHITE wire)
SoftwareSerial mySerial1(2, 3);
Adafruit_Fingerprint finger1 = Adafruit_Fingerprint(&amp;mySerial1);
SoftwareSerial mySerial2(8, 9);
Adafruit_Fingerprint finger2 = Adafruit_Fingerprint(&amp;mySerial2);


Now, you can use finger1 and finger2 for your finger print operations. (previously referenced as only finger)

In order to understand Serial Communication with multiple serial devices, have a look at this Arduino.cc Offical tutorial.

Hope it helps.