Eh, I'm not sure having Captain Jellico in "Chain of Command Pt. 1" (S.6 Ep. 10) tell her to put on a uniform actually made her qualified to be a bridge officer. According to "Disaster" (S.5 Ep.5) she was already a Lt. Commander (or equivalent; I can only assume that counseling was considered a separate structure (not dissimilar to the Diplomatic corps) at the start of TNG (whereas it had previously been that counseling was in Life Sciences in TOS, albeit with unclear ranking) and this continued through "Disaster". However, by the time Jellico took over for "Chain of Command", counseling had been folded back into the regular ship command structure, with Picard not stressing on the formality of having Troi put on a uniform, but Jellico did. But really Troi should have always been in a uniform, IMO, it never made sense that she wasn't in uniform at least when on the bridge.)