Wow, I should hook you up with my friend! She too is from Texas, her hubby is in the military and she just moved to the area. She's in Yelm, actually. She's also a Christian and likes yoga! Ha! PM me if you want her info, I'll let her know too.
I wasn't totally impressed by any of the Christan schools around here, so we opted to do the Olympia Waldorf School. But it's worth it to check out the options here because you might feel differently. There are a few.
Things to do on rainy days- well, you get used to it! We do everything we would do on sunny days, besides swim!
Play outside, go for hikes, Hands on Children's Museum, Farmers Market in the on-season, the YMCA's, Black Hills Gymnastics.. There used to be a Free School here that had cool activities but I'm not sure it's there anymore. The Stream Team offers local free events that my family enjoys. Sometimes Parks and Rec has things going on, but as a whole I've been really unhappy with the young workers and the way they run the classes.
I hope you enjoy it here! We do.