Hello, there's a website called
VolunteerMatch: Where Volunteering Begins - they show you local volunteer postings depending on your zip code and interest. Similar to you ladies, I was on an H4 visa holder and getting terribly bored when we lived in Omaha, Nebraska. Through this site, I'm happy to say that I volunteered at a local community college teaching english as a second language and also at a children's museum - both were highly enjoyable and rewardhing experiences and really helped me once I was ready to start working too.