I started sewing when I was 9 in a 4-H program, and the machines were all old, and we never got the same one twice.
It taught me how to thread and wind a bobbin on anything..how to deal with tension and thread. I don't think the machine matters half as much as the hours spent on it.Don't sweat it too much...kids are very adaptable.
I did see, though..that the new Janome entry level machines come in wild colors(hot pink, purple)...so that may be a way to go.