Up until just before World War I, 1914-1918 in this country, families had a tendency to stay together. They lived next door or just down the street. They may have moved to the next Township or possibly the next County, but that is about as far as you can expect them to have gone at this time. These will give you clues to her maiden name. When transcribing census records, make sure you write down the names of everyone in the household, especially those who have different last names.
Every clue is important.
You may not understand what to do with them or what they mean at the moment, but eventually you will find some other clues which will lead you back to your carefully taken notes. Review your old notes on a regular basis. You'll find there's a lot more information there than you realize. After you've exhausted the Census records you'll find that you now have some idea of where your ancestors lived at a particular date and time. It's time to start writing to local Genealogical and Historical Societies to see if they have any information on the people that you're researching.