I didn't get them all right the first week or so but I do now. I credit my 4 semesters of aural skills as a music major. It's tricky stuff. I hope that makes you all feel good.
I love your review, Krista! I wish my oldest (5) would get into LM as much as your older kids do. It looks like it's a fun family activity and I loved watching them.
Solfege isn't necessarily ear training because you can do ear training without it. Technically it's the name for the "Do, Re, Mi, Fa, So, La, Ti" scale. Especially where letter names are used, the usual context for using solfege is in ear training classes. But you could do ear training with letter names and not use solfege. Likewise you can use solfege without specifically doing ear training. There is also rhythm solfege, such as calling a quarter note "ta" and eighth notes "ti-ti", and then counting out a rhythm with it, like "ta, ta, ti-ti, ta".