That is adorable. It's important that a wife/girlfriend be supportive of the hobby. If it is important to him, she shouldn't let it drive a wedge between them.
I myself play warhammer 40k with my husband. I play Dark Eldar/Eldar and we have placed in several of the local tournaments and play apocalypse games on a regular basis. I started playing because it was obvious that the hobby was important to him, and he was going to play with or without me. I wanted to be included and now it is the main thing we do together, and I love it.