Can somebody tell me wher this is from?
Is it a manga?

It looks like the people from the video game Dark Cloud.

Dark cloud 2 to be precise.

Is it me or does Monica seem to be a tad older than Max in this picture?

She is older than Max by a couple years.

This is from the official, Level 5-sponsored Dark Chronicle Fan Book. And yes, Max is 13, Monica is 15.

Max is 13 and Monica is 15? Where do you get that from? I don't ever recall them revealing their ages in the game.

Hmmm...Unless the official site for this game says something about this in their profiles. Whisp, please link me the site you got this info from. If you got it from a site that is...

Please and thanks...

Hand_Of_Fayt said:
Max is 13 and Monica is 15? Where do you get that from? I don't ever recall them revealing their ages in the game.

Like I said above, it's from the official fanbook:

http://www.hlj.com/product/SOF32365