Without doing a whole lot of research your "youth" is 17 and not an adult in DC. The fact that you let her move out of your house is likely a crime. You are responsible for her safety, medical care, and activities. You need to go get her and if you can't you need to file a runaway warrant.
As you can see from the code sections below, 18 is the age of majority. I could not find any exceptions to that. The code below that shows that a Youth has a legal curfew and can be arrested if they are out after that time. Further, as her parent YOU can be arrested if she is out after that time.
So as your friend on this site I suggest you go get her and pin her down until she is 18 or you may end up facing charges.
§ 46-101. Enumerated.
Notwithstanding any rule of common or other law to the contrary in
effect on July 22, 1976, the age of majority in the District of Columbia
shall be 18 years of age, except that this chapter shall not affect any
common-law or statutory right to child support.
(July 22, 1976, D.C. Law 1-75, § 2, 23 DCR 1177.)
§ 2-1543. Curfew authority; defenses; enforcement and penalties.
(a)(1) A minor commits an offense if he or she remains in any public
place or on the premises of any establishment within the District of
Columbia during curfew hours.
(2) A parent or guardian of a minor commits an offense if he or she
knowingly permits, or by insufficient control allows, the minor to remain
in any public place or on the premises of any establishment within the
District of Columbia during curfew hours.