Exhausted mumma with clingy bub. Help please!

I'm posting this on behalf of my lifelong friend who is a single mumma to a gorgeous 7 month old boy.
Gorgeous boy was born a few day premature and was separated from mum for 2 weeks. He had breathing and feeding issues and was in a different hospital than his mum. My friend went to see him and spent many a long day helping to care for him while she was still recovering from an emergency CS.

Gorgeous boy will usually only sleep well when held upright or cuddled. He will sometimes sleep in his stroller and at night will usually sleep in his mums arms while she tries to sleep sitting up. He also has reflux that is being treated with medication.

Sleeping like this is really taking a toll on my lovely friend and she's getting back pain and poor quality sleep.

For those of you that have been there, what can you recommend please? What pearls of wisdom can I pass onto my exhausted lifelong friend?

TIA