Question for those who might know

Hi... For 10 years now I have started my gym workout with 5-10 minutes (depending on how hard I start at it...) on a Concept 2 rower. As I started my journey at the hands of a physiotherapist following motorcycle injuries, I am conscious of technique and happy with mine.

My wife though... she started at the gym with me about a year or two ago. She uses the rower, but I think her posture and technique is all wrong. Unfortunately she gets all upset and argumentative should I try to correct her posture/technique.

She is suffering a bit of lower back pain. She rows with her shoulders rounded forward, and although he middle/lower back isn't completely rounded, it looks to me that the forward shoulders might be the source of the pain in lower back.

I am thinking to ask one of the gym staff to look in on her and give advice... I won't be involved.

Can anyone confirm my thoughts on this back pain please?