Screwtop Wine Bar in Clarendon. Excellent food, close to Arlington National Cemetery, and it’s relatively inexpensive to rent the entire place.

Shirlington is close by. Carlyle is good, but might not be able to accommodate that many people. Also copperwood tavern or palette 22.
Crystal city also has a lot of restaurants:
Maybe Ted’s Montana grill
Pentagon city:
Matchbox or Lebanese taverna
In Rosslyn
Barley Mac, Tupelo Honey, Amuse at Le Meridien

Maybe you could host something at Ft Meyer?

Have you been working with someone at Arlington? I thought they usually had "funeral directors" for burials. I've been to at least one reception at Fort Myer.

I'm sorry for your loss.

Have you contacted the officers club at Fort Myer? I’ve been to receptions there after a burial at the cemetery and they do a very nice job. It makes it easy for you and for your guests.

I’m very sorry for your loss.

Do you have a place rented or a house to host?

My father is being buried at Arlington National Cemetery. I no longer live in DC and need some help with recommendations for either a caterer or restaurant who can cater a meal for about 50 people.