Not questioning the validity of mom's statement that Sarah would never wander off on her own, as I believe that she didnt have any history of doing that, but wasn't Sarsh reportedly acting very strange recently and suffering from delusions that authorities were out to get her (or ssd something to that effect) If her behavior was recently and suddenly extremely different, it might not be a stretch to at least consider the possibility that it may also result in her actions being very different and she decided to wander off despite not having done so before.
Maybe I'm just hating to be reminded that evil people take advantage of special people more than society (and myself) probably realize or want to talk openly about, because then you have to really consider the worst of the worst in terms of terribly damaged, non-human people
She was found so darn close to home though....makes me wonder how she wasn't found for so long, regardless of what happened. The official search didnt last nearly long enough either though, imo.