There is a new respite resource in Northern Virginia. It is called Jill's House and sounds very impressive from what I have heard and read. Unofficially, I have heard that they are working with other area churches to help set up other similar centers and outreach programs to families that include a disabled child.
Here is a Washington Post article about Jill's house:
copy and past this URL to read more:
http://www.washingtonpost.com/wp-dyn/content/article/2010/09/29/AR2010092903265.html
In addition, you can go to Jillshouse.org and visit the website where you can take a video-tour of the facility and listen to some of the families that are served. I was very impressed by the facility after watching the video-tour. It certainly is well-designed and welcoming and is open to families of any faith (or no religious affiliation at all).
I do not belong to the McLean Bible Church but know people who do. They have shared with me that the minister has a disabled daughter and she was the inspiration to begin an outreach program to help members attend services while the children received the care they needed. This respite center grew from that original outreach program. I hope the idea spreads!