I was just browsing through this forum, our family is starting the process of getting licensed for foster care. Thought I'd chime in although I'm not familiar with your area.
Not all mosques are overly friendly, depending on the cultural background of the community. Even myself as a Muslim, I can walk into a mosque where everyone smiles and welcomes and I feel at home regardless of my background, and other places where no one smiles or notices except if I happen to do something wrong, partly because they are not used to dealing with people of other ethnicities. It's unfortunate, but Muslims are by no means monolithic just like any other faith. Is there a large university close to you? I'd suggest getting in touch with a Muslim chaplain at the nearest university (if there is one) and he/she may be able to direct you to the more vibrant community mosques in your area.
Congregational services (Jumuah prayer) are always offered on Friday early afternoons, and a lot of high schools and community colleges have prayers on-site for students. You can also drop in any mosque during any of the five daily prayers--just to get a feel for what the people are like. A child from Afghanistan may never have met a Muslim who was *not* from Afghanistan, so a typical American mosque with people from overwhelmingly different backgrounds may also be a completely new experience for her.