Working chronologically...
SISTER - Marion's obit says survived by 11 siblings. No mention of preceded. This fits as TRUE.
MOTHER - Alvina's obit says survived by 11 children; preceded by 2 dau and 1 son. This fits as TRUE.
BROTHER- Ray's obit says survived by 10 siblings. No mention of preceded. This fits as TRUE.
FATHER - Willard Sr's obit says survived by 10 children; preceded by 2 dau and 2 son. This fits as TRUE.
SISTER - Roseann's obit says survived by 9 siblings. Preceded by 1 sis; 1 bro. This is NOT ACCURATE but PLAUSIBLE.*
BROTHER- Jerry's obit says survived by 8 siblings. Preceded by 2 sis; 1 bro. This is NOT ACCURATE but PLAUSIBLE.*
BROTHER- Edward's obit says survived by 7 siblings. Preceded by 3 sis; 2 bro. This is NOT ACCURATE but INTERESTING.**
BROTHER- Willard's obit says survived by several brothers and sisters. This is USELESS.
SISTER - Dorothy's obit says survived by 5 siblings. Preceded by 3 sis; 5 bro. This fits as TRUE.***
BROTHER- Ted's obit says survived by 4 brothers. Preceded by 4 sis; 5 bro. This fits as TRUE.

* Roseann and Jerry's obits seem to be missing the 2 infant deaths - John and Catherine. While this is not ACCURATE it is PLAUSIBLE as infant deaths are rarely missed on PARENTS obits, they are commonly missed on SIBLING obits. Again, I'd call this PLAUSIBLE.

** Edward's obit is the only one to mention the infant girl by name - Catherine. However, John is missing.

*** Dorothy's obit is the only one to mention the infant boy by name - John. However, it list's the girl as Elizabeth, not Catherine.

WHAT DOES IT ALL MEAN?
Well, when it comes to John and Catherine, I'd say all in all the information is certainly PLAUSIBLE enough w/out getting more information from the courthouse.