I’ve not taken a trunki but we’ve never had a problem taking 3x hand luggage! It’s just a lot to carry so last time coming home I condensed it so me & my partner shared one and my little girl had her own. We just used her changing backpack as it’s huge! So we were able to put everything we need in there x
Just to add - the airlines don’t “advertise” that under 2yos get this luggage. We’ve been with TUI, Ryan air and jet2 x
Depends on the airline. Long haul I could take a changing bag for baby/toddler alongside my own hand luggage, as long as it only had her stuff in. But when I flew with TUI, there was no hand luggage as she was on my knee and didn’t have her own seat x