Italy

Cinque Terre

IIRC from your other post, you're coming from Milan? Frankly, neither is ideal with young children. They aren't exactly stroller friendly, and both locations will be packed with tourists. The CT villages have steep hills and cobbled streets and packed trains between villages. Venice has the stepped bridges that strollers will have to be carried across. But given the choice, I'd go with Venice.

Venice.

But both will be extremely expensive for that many people and probably very crowded.

If you mean 3 nights, making 2 full days, that's very little time in either location. If you mean 2 nights, with 1 full day between, it's even less.

Full disclosure:

I find Venice fascinating. I've been there 3 times. The last one I rented an apartment for 5 nights. There's no place else like it.

I've been to the Cinque Terre once and found it so overcrowded that I will never go back. I just don't get the hype.

We half day day tour would you recommend leaving from Zurich to see the alps?

You might consider a stay on Lake Garda or Lake Maggiore.
Both are flatter, easy with large group and babies.

Venice, but I wouldn't try to do everything all together all of the time.
You might ask your Switzerland question in the Switzerland forum?

Half day tour of the alps from Zurich? I really don't know as Zurich is not in the mountains.

Sooo we are now looking for cheap airfare to fly from Zurich to either Pisa or Genoa. I can't seem to find a nonstop flight to either city. We would be leaving Zurich on Aug. 31. Thanks for your help!

I don't see any non stop options either- using Google flights.
Best bet looks like ITA with a change in Rome to Genoa

Where exactly do you plan to end up now?

Train from Zurich to Genoa is only about 5.5 hours. Cheaper, easier.

Thanks! It looks like I can’t book any rain tickets until 2 months before traveling. Do you think we’d have trouble getting 12 train tickets from Zurich to Genoa at the end of Aug? 5.5 hours is doable as we can walk around in the train (have 2 small children) Would I book through RailEurope??

Schedules probably not up yet
RailEurops is a reseller
You should book on the Swiss train site
Maybe post this question in Switzerland forum