Think was definitely the norm especially all those years ago to put soiled items in a bucket in either the kitchen or bathroom regardless if there were men in the house or not and can remember lots of other people doing this when I was younger. Work in mental health and can say that paranoid schizophrenics are usually really chaotic and is highly unlikely that Sheila would be so unwell as to murder her whole family after being rational enough to think about soaking her soiled clothes.
To be even handed, June could have soaked the knickers and rinsed the tights earlier. In which case, what was Sheila wearing, if anything?
My problem with the Sheila scenario is, how can she be both organised and - your good word - chaotic?