The main stem and any stems can quickly recover from snapping , if the stem is not too broken then no need to add suport like tap or wire anf if the stem is really half broken and more then a little bit of support will help her to bounce back. Cannabis is very resiliant when it comes to little injuries like that . It would have been a problme in flowering because it could have stunted it but in your case the plant will slow down on the vertical growth during less than a week but the secondaries will take advantage of the situation to grow stronger.