what is my newlyfound sister feeling?

A year ago, I found my adopted sister, who will be 50 this year. She is 10 months older than me and was the 5th child of my mother & father (I was #6). When my mother was pregnant with her, she & Daddy had little more than with 4 small children. Serious financial problems plaqued them and she felt she couldn't care for the kids she had, and her baby deserved more. She found through a friend someone who wanted a child and could provide everything for her, so she made the sacrifice. Soon after, she & Daddy realized that the pain was too great and decided to have another child (I guess I was a "make-up baby") and I was concieved within a month of Mom "losing" my sister. This adoption was never discussed while I was growing up, but when I was pregnant with my first child, my oldest sister told me that she thought Mom had lost a child because she had remembered that Mom was pregnant and went to the hospital and returned with no baby and was very sad (from the eyes & heart of a 5 year old). I asked my mother about it, and she told me the truth. She said it was a very difficult time in their lives and she was ashamed that she couldn't care for a child they created. She also asked me not to mention it to my father because of his pride. After my father passed away, four years ago, my sister and I asked my mother if we could start looking for our other sister. Mom said that would be wonderful, because she would like to make sure she had a "better" life. Armed with little information, my sister, Becky, and I searched & searched, but found nothing. Soon, Becky became ill with cancer and the searching reached a standstill. After we lost my sweet Becky, I continued the search, as much for myself & my mom as for my Becky. Well, Thanksgiving last year was indeed "Thanksgiving", I found her. We compared notes and were reasonably sure, until we met...there was no need for DNA testing!! She looks so much like my oldest sister, it's scary. We are definitely sisters!! The most remarkable thing is that her adoptive parents named her...you guessed it, Becky. She has truly been an angel to me. What a blessing! My mother has met her, as have my 3 other siblings, but Becky and I share a bond that is unexplainable...and remarkable. I love her with all my heart and feel that we have known each other forever. We are in constant communication and see each other as often as possible, in spite of the miles between us. I guess my problem is that I worry about her emotionally. She seems to be handling everything wonderfully, except talking to her adoptive mother. She mentioned me to her when we first were in contact, and was met with anger and fear. Her adoptive mother told the 49year old daughter that she was not allowed to have anything to do with "that woman" and I had no right to contact her. (She wasn't aware that Becky has contacted me, too). AMother told her not to talk to her father about it because it would hurt him too badly. I know that this is extremely hurtful to Becky, although I try not to pressure her about this. She invited me to her daughter's college graduation & party afterward. I went and AMOM was there. I was introduced as a "friend", but I suspect Becky's plan is to let her mother see I am a nice person, the reveal my true identity later and show that I am not the evil child-stealing woman she thinks I am. I guess this long explanation is to find out what emotions Becky is going through and to find out if anyone can suggest ways I can help her deal with this. We've discussed the fact that she is lying to her mother, but she feels that is better than hurting her. It bothers me that I was thrown in her face. (We do resemble each other a lot, so AMOM may already suspect) But it bothers me more that Becky has lied to her mom. What can I do to help her? What is she feeling?