Postpartum Support International have recently set up a group specifically to support moms and families with experience of Postpartum Psychosis in the USA. Here's the link
So sorry to hear that your sister is suffering from Postpartum Psychosis. It's a very worrying time for everyone in the family, and I'm glad you have reached out. There is a link here for family support with PSI - they will be able to help, and have good knowledge of the mental health system in the USA to advise you.
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