I have put for you below the link to BCC's publication regarding LCIS and hope this may help. I don't know if you may be able to get some or part of it translated for your sister in law?
My sister in law who lives in Mexico and does not speak English has just been diagnosed with LCIS. I wondered if there was anyone who had the same and what they are doing. She has been offered 3 choices - regular check ups, tamoxifen or double mastectomy.