New drink: the ginger rose

I made up a drink for my sister last night; she likes them "not too strong" (I have to put that in quotes since I'm not sure what that means).

Ginger Rose

1/2 lemon
1 1/2 to 2 oz vodka (depending on your tastes)
1/2 oz Cointreau or Triple Sec
dash angostura bitters (optional)
squeeze of fresh ginger juice (press a chunk through a garlic press)
soda water

Muddle the lemon in a cocktail shaker. Add ice, vodka, Cointreau, bitters, and ginger. Shake well to mix. Strain into a highball or double old-fashioned glass, add a few ice cubes, and top off with soda water to taste.