If she gets stopped for a traffic violation in another state that could be a problem if it comes up there is outstanding warrant in DC>

There are a lot of ifs.

Has she been busted before?

What are the charges?

Do they have a strong case?

Generally speaking, it's not a good idea to become a fugitive.  It can come back and bite you in the ass some day.

(still not a lawyer)

I have to agree that becoming a fugitive is a bad idea.   If she does not appear a bench warrant might be issued...   someday, years from now, a simple traffic violation ends with your friend in the back of a squad car with twin braclets by Smith & Wesson.  It takes a misdemeanor & raises it to something that'll stay on her record.
I'm dropping a link below which discusses penaltities & diversion programs...  see what she might be eligible for.    
I think she needs some legal consultation before doing anything & to see if she can get this straightened out.   It might just be possible to pay a fine & then never come back.   Some areas will accept a plea to a lesser offense that doesn't sound as bad like disorderly or something...  

and have initiated a "safe surrender" program to try to reduce this number.

      So realistically a lady would have to be unlucky to be pursued for a state misdemeanor arrest. But why take the chance - that bench warrant will issue and then you face serious legal jeopardy.

The "flight rather than fight" impulse is hard to suppress, but as a "professional defendant" who's been in court more times that most lawyers (charges not related to the Hobby), I can advise it's always better to stay and fight. There needs to be closure on this charge so it can't resurrect at some point in the future and Murphy's Law says it will raise it's ugly head at the least opportune time.  After the decision is made to face the system, there are lots of viable alternatives. Rule One is invest in a good lawyer! I've managed to not be a "Guest of the State" for even a night, thanks to good honest attorneys.