Hi, S.. I think you're on the right track. A church group would be a great idea. Is there any way, though, that you and/or your husband could get some kind of a small play group together? I think that because your daughter has never played with kids before, she doesn't know how to do so, and is used to interacting only with adults. I think if you and/or your husband could just get on the floor with your daughter and a couple of other kids her age, and just play with them, she will see what is appropriate and follow your example.
You know, just playing with blocks or dolls or musical things is a good way to show her how to get involved with other kids. She may not be old enough to understand how to play any kinds of games yet, but once she breaks the ice by doing the toy thing with kids her own age, she will understand how to relate to other kids, and then you can show her and a couple of other kids how to play very simple games like rolling a ball back and forth.
Maybe you can ask the other moms here on this forum if anyone is close enough to you to form a playgroup? I do think that you have something to be a little bit concerned about, but not worried yet. You do, however, want her to be comfortable with other children her own age WAY before it's time to take her to school or daycare. Maybe even put up a flyer in the local grocery store asking parents of kids her age to get together in a local park. That way, no one has to have strangers in their own house for the first time, and then you can make friends and invite them over for indoor playdates.
I hope these ideas are helpful to you, and that your daughter absolutely thrives socially! She sounds absolutely delightful!
Peace,
Syl