This seems to be a very rare name, but it's not completely unique.
At the ancestry.com site, there are two girls named Sinaloa in the California state birth records they have:
Sinaloa M Mills, born 10 Jul 1972 in San
Diego
and
Sinaloa
Maureen Pike, born 7 Sep 1953 in Los Angeles.
Ancestry.com has another reference to Sinaloa Pike: she was married to
Ralph Donovan in Las Vegas,
Nevada on 28 Nov 1970.
The Tennessee marriage records on Ancestry.com show a Sinaloa
Sylvestre marrying
Ricky Harvey in Sequatchie County in 1979.
The California divorce records have a Sinaloa Peregrina divorcing
Robert Ledesma in October 1970.
The Social Security death records have Sinaloa Hobson (born in 1927) dying in Suffolk County, New
York in 1980.
Finally, there is a six year old girl in the 1880 census of Pike County,
Indiana, listed as Sinaloa Phillips (daughter of D. J. &
Almira).
You always have to take records like this with a grain of salt, as there are many mistakes and misspellings in them. However, since there are two different records of Sinaloa Pike
Donovan, I think we can be reasonably sure that she is a real person who was really given Sinaloa as a first name. So if you yourself are not Sinaloa Pike
Donovan, you can be fairly sure you have at least one namesake out there -- and you probably have several others.