I don't want to "over-discuss" the issue. But in my opinion the OP's statement that she was a citizen had no purpose nor benefits. The whole purpose of the law to punish false claims to obtain employment or benefits under state law. The OP's sentence (not even a claim) was purposless and benefitless. I see no reason why USCIS would deny her application unless they do not read the explanation.
She had no reason to check YES for the question. I am surprised the IO did not ask her to correct it to NO!
The guidline:
False Claims to U.S. Citizenship Falling Under 6C2
4. False claims to U.S. citizenship made on or after Sep. 30, 1996 should
be examined under new INA 212(a)(6)(C)(IL) ("6C2"). This provision
significantly expands the scope of the ineligibility related to false
claims to U.S. citizenship. 6C2 applies not only to false USCIT to U.S.
claims made to obtain U.S. passports, entry into the U.S., or other
documentation or benefit under the INA; it also applies to false claims to
U.S. citizenship made for any purpose or benefit under any other federal or
state law. Thus, a false claim to U.S. citizenship, for example, to obtain
welfare benefits would fall within 6C2 (provided the claim was made on or
after 9/30/96). A false representation of U.S. citizenship made for the
purpose of voting in a federal or state election could also be a basis for
a 6C2 finding. (This would be in addition to any ineligibility finding
which might apply under the new unlawful voting provision of INA
212(a)(10)(D)). In addition, 212(a)(6)(C)(IL) expressly covers false USCIT
claims made for any purpose under INA section 274A, which makes it
unlawful to hire an alien who is not authorized to work in the U.S. Thus,
an alien’s false claim to U.S. citizenship in order to secure employment in
violation of INA 2-4A would justify a 6C2 finding.
5. As noted above, 6C1 only applies to misrepresentations made to Consular
Officers, INS officers, or similar USG personnel. Conversely, there is
nothing in the language of 6C2 which would require that the false claim be
made to a U.S. official involved in implementing some aspect of the INA.
On the contrary, since the statute covers false claims to U.S. citizenship
made for purposes or benefits unrelated to the INA, the language of the
statute would appear to presuppose that in at least some cases the false
claim will be made to a federal official outside the Department or INS, or
to a State official, or even to a private individual (e.g., in cases where
the false claim to citizenship is made to a prospective employer to
circumvent INA 274A).
