I've got this problem on the occasion with my machine, though not the one she has.
I found out that my machine (brand new I might add, a mini-machine, too) is very, VERY picky with the kind of thread I use. I was trying to use polyester/cotton thread and every time, the machine would clunk after a few stitches and the top thread would break. I don't know how many times I re-thread the machine, take out the bobbin, even rewound the bobbin, I still had that issue. I changed out to another thread, no more issues.
100% cotton through my machine, no clunks and no breaking of thread. I would also suggest that she figure out just how old that thread is, my older Dressmaker doesn't like older thread, if I'm sewing and I break the thread too many times, I swap out the spool with a newer one and it stops.