Jackie,as I've already mentioned, a young Jeremy would not have known,nor even understood Sheila's " medical problems ",losing babies,then giving birth and the physical and mental changes that occur with these processes. How would he have been expected to have known ? Things like that were swept aside,let alone mentioned in the WHF household where June was concerned.
I'm sure had Jeremy have known of Sheila's plight,he'd have been the first one to have offered help to his sister. Afterall,wasn't it Jeremy who'd made sure his sister was safely taken home after a party ? I wonder how many times that happened ?
If there'd been any way of helping Sheila,I'm more than certain that Jeremy would have offered.
I too think they were as close as any ( blood ) brother and sister,in fact more so.