P.S. But the wine shop recommendation was really the right answer. MacArthur and Calvert Woodley are both excellent. Also Rodman's (Chevy Chase) or Schneider's (Capitol Hill).

I'm going to risk a specific recommendation. I haven't met a red wine drinker yet who didn't love Turley zinfandel once they try it. Many different vineyards and price points from $29 to $100, most in the $45 range and all fabulous. Ridge also makes wonderful Zin. And Dave Phinney makes (or used to, anyway, I hope he still does) an amazing proprietary red blend in Languedoc called D66. It's not everywhere--you have to poke around.

A caveat: these are the full, accessible style that came to be referred to as "fruit bombs" (though they're not the extreme, high-alcohol examples that came in for some deserved derision a few years ago). They would not be mistaken for restrained, aged French reds that have "tobacco," "leather," or "forest floor" in their descriptors.

I second the suggestion to go to good wine shop. They will have lots of suggestions for quality winemakers or interesting wine regions in your price range. Most wine lovers appreciate trying something new. If you know what kind of food she likes? Her preferences for food could provide clues as well.

If that's not an option, most people find these wines enjoyable.
Red from the Rhone Valley, France is a good bet. It's versatile with food, and the overall quality of the region is good.
A Santorini or Assyrtiko from Greece for a refreshing, aromatic white that is typically dry.
A rose from Provence. I haven't met too many people who dislike rose. It may be a bit early for this year's release though.
Italy has some truly unique wines, including a Valpolicella Ripasso, Nero d'Avola, and Barbera d'Alba that are available in that price range. There can be some bad examples though.

You might also consider a wine experience, instead of a bottle. Local wine shops host tastings and pairings.

I would avoid these popular wines as a gift: California Chardonnay, Zinfandel, Australian Shiraz, New Zealand SB or Argentinian Malbec. Many wine drinkers tend to love or hate these types of wines.

Go to Bassins (MacArthur) or Woodlley Calvert. Ask for guidance.

I’d like to give a gift to someone who loves wine, but I have no idea what her specific preferences are. Are there some well known wines in the $50 price range that pretty much everyone would like? I was thinking a bottle of red and a bottle of white. Or is it a bad idea to give wine to someone if you don’t know the specific kind(s) they like? I’m flying blind here. Any recs welcome.