Great family friendly restraunt nearby would be Il Pomodorino.
Walk out the front, turn right and then a block or two. Right again (before you go through the arch and into the park, and walk 100m. On the right side.
Three were some Italian families with kids there. Very friendly, not as spendy as the cafes on Via Veneto. Great delicious food. Reminded me of Pasta Pomodoro on "Steroids". Upscale enough so you don't feel like your eating at a chain (although you may be), but not too spendy so that you cringe.
The first time we (2 people) ate there it was $115 the second time was $55. I think the first night we had green salad, tomato and mozzerella, pizza, 2 entrees, 2 bottles of wine, beers and dessert. Way, way, way too much food. But it was our first night there.
We knew what to expect the second dinner there, ordered accordingly, and got out for half the price. Still did the beer and wine, pizza, main (1 or 2), and split a dessert.
The waiters are friendly and aren't gonna try and rip you off but... if you order it there gonna bring it and you'll have more than you can eat.
House wine was very drinkable at like 8 Euros.
I live in the Bay Area. I pay $100 for 2 including dinner and drinks regularly (
). In that perspective this was a good value, but certainly more than a dinner at Pasta Pomodoro.
Regards, Scho
PS: Supermarket up the street through the subway station. The bottled water in the mini bar is way over priced. Also a small cafe called "American Bar" just a across Via Veneto, continue and then turn right. Essentially it is facing the buildings that back up to those that are across the street from the Westin.
The thing that I found most disorienting was the hours that shops kept.