Dave in TN wrote:
The DC Metro system is reliable, affordable, generally safe and easy to navigate. Unless your daughters are younger than I'm assuming, I'd consider dropping them at the Greenbelt Metro station which is just off the beltway on the north side of the city and let them Metro in. Many hotels in the city are a quick walk from a Metro station. If not, Uber is an option.
Good Advice. Find a metro station near your route and use the kiss and ride lane to drop your daughters off. No parking required.