I will be taking a train through France, Switzerland, and Italy with my 21 year old daughters. Can we ride together if I purchase youth (2nd class) passes for them and a 1st class ticket for myself (it appears I'm forced to purchase 1st class as an adult). Can the three of us sit together in second class during our ride even though I have a 1st class ticket?
1) Yes, you are allowed in 2nd Class. 2) I'll bet you'd do better with tickets instead of passes. Possibly lots better.
as always particularly in france and italy it's better to crunch the numbers for point-to-point tickets and compare that to rail prices. however the savings for youth passes are so significant that those still might be cheaper. you could potentially buy yourself point-to-point tickets and get railpasses for your daughters. reservations on high speed trains in france and italy are mandatory and extra for railpass holders, though, so you'd have to factor those costs in when comparing between the two.