Is she pulling up the bobbin thread when she starts the buttonhole? If she does that and then holds both threads for the first few stitches it should help. Also, if she uses a stabilizing paper underneath the buttonhole, that should also help. I find that using gimp thread in the buttonhole foot usually helps. There's a little notch at the back of the buttonhole foot that you catch it on, then cross it at the front of the foot and secure it in the little hook that is there. Hope this helps.