I found this, which isn't any help.
1910:
Butterfield, Barry, Missouri; Roll: T624_767; Page: 6B; Enumeration District: 2; Image: 658.
[Indexed as Permington, looks like "
Pennington"]
William E Permington, 28,
Missouri,
Ark,
Ark, boiler maker for railroad
Rebecca A Permington, 16,
Missouri,
Missouri,
Ky Hawell E Permington, 3, OK, MS, MS
Jewell E Permington, 1 5/12, OK, MS, MS
Rebecca and William have been married for 4 years. She has had 2 children.
1920:
Tulsa,
Tulsa, Oklahoma; Roll: T625_1487; Page: 1B; Enumeration District: 232; Image: 362.
Wm Pennington, 38
Rebekah
Pennington, 26
Hewel
Pennington, 13
Jewel
Pennington, 11
Leo
Pennington, 3 3/12
Joe
Pennington, 8/12
I googled
"Rebecca Marie" Mashew
(with the quotes as shown. The name is rare enough that search argument will find both "Rebecca Marie Mashew and
"Mashew, Rebecca Marie".)
Google suggested
Mayhew, and I remembered a young man named Mashore that I went to school with. There are just 16 people named Mashew in the USA in the 1900, and half of them have corrections to "Matthew" or "Mathew". I would bet even money that even if "Mashew" was the correct spelling, she got recorded in 1900 as something else. There are no Rebeccas or Maries or Rebekahs or Beckys named anywhere close to "Mashew" in
Carroll County on the 1900.