Not sure where you are going with this Sherlock?
There was a lot of blood all over the farm house ....
There was a fair amount of blood on the Bible ...
There was at least a "smear" of blood on at least one of Sheilas fingers ...
The above should be facts agreed by every body ....
I believe Sheila had a shower at some point that evening or night ....
Why take dirty clothes off and put a clean night dress on if she had not had a shower first ?
So I want to work out at what point she had a shower - was it :
1) Before supper ?
2) Before the shootings ?
3) After 4 of the shootings ?
Also even if it appears to lead nowhere or to be irrelevant I think every unanswered question in this case should be answered - the nearer to having all the facts the nearer the truth we will be ...