Suspect my sis has PND. How can I help?

[Choccybadger]

Posted this on wrong section last night - having a brain fart

Please can anyone advise how to raise this with my sister so she doesn't feel like I, or anyone else, is being critical of her as a Mum. She has a tender to feel attacked if any suggestion is made as to how she may benefit from doing anything differently. Very defensive and upset/angry.
She is extremely capable, loving and has a great bond with her baby and he wants for nothing in terms of attention, feeding, play.
It's my sister I'm worried for. She had a rough start, with emergency section and baby in intensive care. He is a crier and allergic to many foods and there is possibly something wrong with his stomach - undiagnosed as yet. She has never left him, even for 20 minutes. Even if hubby is with him, she is there.
She is so exhausted and fraught with worry that I can see a big crash coming.
She keeps making hubby take days off work to stay with her even though I have repeatedly offered to go over. Worried he might lose his job or at least it might make things difficult for him at work.
How can I help her?

[Millionairerow]

A difficult one. Best way is to get her out seeing other mums so she can compare notes. It'll be the least thing she'll want to do but needs to know she's not alone. I think I had this without knowing it though. I felt v lonely though and wished I'd made more friends with babies. She may feel she's fine. Or offer to let her get some kip while u mind the baby to refresh the batteries.