Hello guys I’ve got a problem.How can i make image for my game?
Girlfriend of my brother is tatoo artist and she draw some characters.
Is it possible to put it in the game or i need speed painting guy ? 
Everything is possible. You just need to get your tattoos into the game somehow. Scan them in, clean them up in a painting software like Gimp or Photoshop, and there we go.
In the beginning game art was made by really drawing all graphics by hand. The technique is called pixeling. Because in those days it was really painting pixel by pixel. Scanning in handpainted images also falls into that category.
Here are some tutorials how to do 2D game art by pixel technique: Pixel Art Photoshop Tutorials For The Pixel Lovers - Hongkiat
Most common techinque nowadays is using 3D models to create the artwork for games. For 2D games you render the 3D graphics to bitmap. For 3D games you directly use the 3D models.