It is either the Isabella is professional, or she is a hacker.
If you were playing in a normal channel, the chances are that she/he is a professional.
If you were playing in a beginner channel, the chances are that she/he is a hacker.
How to detect if it's a hack?:
To detect if a person is hacking, you'll need the hack file he/she is using. If he/she is using a rapid fire, then you'll need rapid files, which help you see if the person is hacking or not.