sun I suppose the question is, do you yourself want her to be in a bra or thigh-banded? And if so, why? Thighbands serve two purposes: the make masturbation even more impossible, and they construct the wearer’s legs. You aren’t concerned with masturbation since she has no secondary shield (and thigh bands would not help,) so it comes down to whether you feel her stride must be limited. And that’s more of a bondage than chastity question.
The bra, similarly, exists only to prevent nipple stimulation and to act as a mental reinforcement of control. If you don’t want one or both of these things, there’s no need for a locked bra.