I doubt Patsy ahd anything to do with the crime. But I also doubt that Patsy did not know who did it. In that sense, she was complicit.
In many respects, Patsy Ramsey is a tragic figure. What would you do if your husband or son did something like this? Would you elect to lose TWO family members, or deal with the situation inside the family and lead the investigators astray? I can't say what I would do, but I am not certain I would have cooperated with the authorities if it meant losing my son or spouse in addition to my daughter.
In fact, I might even write a note to throw the authorities off track....