During the last few years, 75-year-old mrs. esterhouse has gradually become so mentally disoriented that she can't find her way around her own house and often fails to recognize her husband. it is most likely that mrs. esterhouse is suffering the effects of:

Hey there!

Mrs. Esterhouse is likely suffering from Alzheimer's disease. Alzheimer's involves a decline in thinking and memory ability and sufferers often become much more disoriented and unable to recognize familiar surroundings than before. It's a progressive and degenerative disease without a known cause that's one of the causes of dementia. 

Hope this helped you out! :-)