How Can I get Her To Commit

Im in a tough long distance relationship with a woman who is half my age. We have a son he is 20 months old.. We have been planning on getting married for a year now.. we even went as far as to get a wedding ring and even went to court and got a marriage license.. Here is my problem her sister is totaly agains me getting married she said Im to old for her sister.. she also got her into this church that has some members convinced that she should not get married to me. anyways everytime she decides to get married she then some how changes ger mind and the wedding is off.Now Im in WA were she lives and we were suppose to get married in florida and I was to come here and help her get her things and now she has said she cant go along with it... How can I get her to stop listening to what all these people are telling her.. she does love me and tells me that I make her very happy but she just cant stick with her decisions and follow thru.
And Im running out of patience. I have not put any pressure on her because if I had we be married..I want her to say yes and commit and not change everytime..how can I get her to feel that she is making the right decision..I feel like all this has her somewhat nervous and she might be afraid..and the fact that we live so far apart does not help.. whats a man to do.Im going crazy.