She has a medical issue that is none of your business.
From the Internet:
health issues such as placenta accreta and preeclampsia as risk factors
Her diseased ovaries can't produce anything
Well, probably she has some health problems or something of the kind... My family is also thinking about such surrogate agencies because we want to have a baby and I guess that Surrogacy in Greece is a great variant for us right now. Do you agree with it? I would like to hear your opinion.