there is a lot of speculation on this situation without support. We do not know why the RO was sought and issued. For all we know, GF threatened mom with violence. If so, it has nothing to do with OP.
If the order was sought on behalf of the OP or it was based on the OP being a minor and was for the protection of OP as a minor, then OP could seek to have it vacated once OP turned 18.
so, as usual; more info needed to be able to address this
If OP is a covered party in the order, even if the order was granted for the protection of the stepmother after threats of violence against her, per your speculation, OP could still request modification of the order on his 18th birthday to exclude his coverage.
If OP is not a covered party, the point of the question is lost on me. If OP isn't a covered party, the girlfriend would not be in violation of the order if she sees OP today, so long as she does so in a location not covered by the order.
In any of these cases we are working off a bare minimum of information. I certainly welcome the OP to provide more information so that he can receive more targeted and accurate assistance.