If you are having difficult thinking spelling variants for your last name, remove vowels or change each vowel with another one. Vowels are the letters most likely to be the cause of spelling variants. Neil easily gets spelled as Neal, Hull as Hall, etc.
There’s other letters that can be a problem, but vowels are a good place to start.
If you had an aunt or an uncle get divorced, have you considered looking at their divorce records? There may be mention of where they married or where they lived when they were first married. Either of these items could be clues in researching your direct line ancestor. And there is always the chance that your ancestor provided testimony in the divorce of a sibling.
I’ve encountered instances in my research where children have provided maiden names of mothers that were inconsistent with information provided with the mother and that were completely wrong.
I’ve also encountered instances where the children gave a last name for the mother that I thought was “wrong,” only later it turned out to be right.
While information children provide about their mother’s maiden name is secondary, don’t assume the children are clueless. Sometimes they are…but sometimes they are not.
Don’t neglect to tell your own story in addition to those you discover on your ancestors. After all, most of us would love to have something our long-deceased relative had written about themselves. Be certain to include what you remember about relatives you knew growing up as well.
And who knows, when writing your own stories down, you may get some insight into that ancestor who has you stuck