((((((((((hugs))))))))) and prayers going out to you and your family,
Patie!
I understand what you are going through. I am 47 and my sister is 50. She "came out" as a Lesbian 18 years ago. Some days it still blows my mind! Although all of us had had some suspicion about it through the years, it was still a shock to actually have it confirmed. Luckily, because I had had suspicions and had thought about this possibility, I reacted in the best way I felt...I hugged her and told her that I loved her and that she was still my sister! And she is the sister that I have loved through the years, no matter what. As uncomfortable as I was about this aspect of her life, I knew that I couldn't stop loving her.
Your family has done the right thing in telling her that they love her. It would serve no purpose to cut her off. She is not going to change and it would be futile to try to do so. Having a Gay or Lesbian offspring or sibling is a real test of unconditional love, especially when you are a Christian. There is going to be a lot of confusion and frustration on everyone's part. You may never feel totally comfortable about this, but with time things will calm down and you will ultimately have a sense of peace.
I realize that this lifestyle is sometimes hard for my sister as well. I am thinking of a job that she had to leave because of discrimination she faced when co-workers found out her sexual orientation (yes, this still happens!) I am also thinking of the time she broke up with one of her more caustic and uncaring girlfriends and she had a nervous breakdown over it and had to live at my house for a month ( I realize this could happen in a heterosexual realtionship as well).
Please PM me is you would like to e-mail. It is hard to find support as a sibling of a Gay or Lesbian person. People always recommend PFLAG (Parents and Friends of Lesbians and Gays). While they are a good organization in some ways, I found some of their beliefs extreme for my taste. The best thing for me is to just keep in prayer and be aware of my own reaction to the situation. It is always best to approach this matter with great love and understanding and I feel that that's exactly what you are doing.
You and your sister will both benefit greatly because of your caring!
I know this is a hard time and I am here for you

Kathryn