My family will travel in Italy soon and we will primarily taking train between cities. I am debating between 3 carry-on sized luggage(21") or one carry on and one check-in (~26"). The main concern is that I could not count on my daughter (9 yrs) to carry the case all the time and I do not want to have both of my hand occupied. So my question is will a 26" case too big to fit in the luggage rack on the train? Thanks.
I think that a 26" case will definitely fit in the luggage rack. The only problem I see is that with a larger suitcase we pack it fuller and then it is heavier to lift.
There are luggage racks at the end of each train car and your can put our large suitcase there - you might want to take a cable lock (like a thin bicycle lock) so that you can lock your suitcase to the rack and no one will walk off with it.
Larger bags are manageable as suggested in above post. They are more clunky to sling around and heavier. Alternatively, try using an 18"backpack for your child or very small suitcase or duffle with a shoulder strap. Then, your child can carry some or all of her own stuff. If possible, let your child pick out a fun color. My daughter rolled her own case all over Scotland when she was 7 and was proud to do it. Another option is the RS euro tote or similar where the tote has a back snap panel that can be secured over the handle of a rolling suitcase. Then, get some eagle creek or ebags packing folders and cubes to compress the clothes and maximize the space. Your 9 year old should be able to cart her own stuff. Just don't allow excessive stuff and stick with the basics.