1930 Census--Marilyn Monroe
The Marilyn Monroe Facts Page at http://marilynmonroepages.com/facts.html indicates that Marilyn (formerly Norma Jean Baker) lived with the family of Albert Bolander at 459 E Rhode Island St., Hawthorne, CA, from 1926-32, which is the address of this enumeration (noted on the side of the page). There are other references that provide similar information. Numerous sites indicate that Norma Jean's mother, Gladys, also lived with the family at various times during this period.
There are a few errors in this enumeration, most notably the age (which should be 6--unless it is to indicate 6 years and some months) and the places of birth listed for Norma Jean and her parents. This Norma Jean is listed as being widowed as well. I don't have the answer for this particular discrepancy. However, given the family structure it is likely that whoever answered the questions for Norma Jean was not certain of all the answers.
Gladys Baker's husband, Mr. Baker, went to Kentucky after his divorce from Gladys and this Norma Jean Baker is not his mother. As Gladys was likely estranged from the Baker family, I find it difficult to believe that a member of the extended Baker family would be living with Gladys at the Bolanders.
It seems really coincidental that Marilyn Monroe (formerly Norma Jean Baker) lived with the Bolanders in the late 1920s and early 1930s and yet there is ANOTHER older Norma Jean Baker enumerated in their household and younger Norma Jean Baker is somehow omitted.
If you think she's elsewhere, give a search of the 1930 census and let us know if you find another potential match.