How do I found out when someone is being released from a 72 hour hold?

Coz they will not tell her $ all it's about only 72 hour hold they will try & lie only court order can keep them longer

Why does she not know how long she will be there? or information given to her husband?

You can probably count on them being there an average of 7 full days. You'll have to have their patient code before they'll give you any information over the phone including if they're even a patient there.