I realise that this is likely to be a US story where effectively it's the Wild West and women no longer have power over their own bodies when they enter into these agreements but there are some interesting points in the video and the update text (sorry I can't c&p).
She had twins for a Chinese couple who paid extra for her celibacy and paid her 'handsomely' for the surrogacy inc breast milk, and more for when she followed their nutritional plan.
Her sis and BIL aren't paying her above expenses but they have a 120 page contract. It sounds very much coerced as she didn't want to have another pregnancy but because they spent thousands on infertility treatment and she had already been a surrogate mother she was probably persuaded, it doesn't sound voluntary to me.
The BIL thinks no man (her boyfriend) will be able to control himself and not have sex with her during the pregnancy despite the contract which says no sex allowed. He doesn't trust her to keep her word but also thinks men can't manage without sex.
For anyone who thinks altruistic surrogacy through family relationships is better or more acceptable than commercial surrogacy I think this would be recommended viewing.
It was posted two weeks ago.
which by the sound of it I will need, to watch later.