You can still relax. I think it won't do harm to take her to a speech therapist if she is still not saying it a few months before she starts grade 1, but before that it's not necessary. Children often start saying the "r" in a "trrr" or "drrr" sound, not in a word, but on its own. You can also let her practice to say "te-de-te-de-te-de" (etc.) faster and faster, moving on to "te-dap", "te-dop", "te-dip", "te-dok", etc. at some stage. The idea is that a fast "te-dap" becomes "trap" and so on.
BUT, keep it very relaxed and don't put any pressure on her, if you even decide to help her with it at all. You don't want her to become too aware of the sound she is not saying yet.