If you have knocked on the front tooth before, I think the most important thing is to establish the health of the tooth, any tooth that has been traumatized before there is a slightly increased chance of the tooth dying whether you are doing braces or Invisalign.
Of course, if you use higher force to move the teeth that is a slightly higher chance of that happening but I won't say that it is not suitable for braces because I do treat a lot of patients who have front tooth injury before with braces but I think you need to understand the risk involved and then let the dentist or orthodontist know that she has an injury before so that we can monitor this tooth throughout the treatment and we try to use a more gentle force as we are moving this tooth as well, we do need to check this tooth periodically if something happens to this tooth as the tooth dies off then we just have to manage it this tooth accordingly.