Brenna nearly jumped out of her skin when Sterling came close to creampie turf with her at the hotel - she aint likely to be in a rush to get pregnant with him, not by anything but accident at least and being single would make it a hard sell to her family as to whom the father is as well.
As for vaginal sex though - i think its not too far away, prob not this next upcoming update as shes in a spell at the end of the last one processing what actually happened between them but shes clearly not far away and the one who will be first amongst the family to go all the way with him esp with Eva on board pushing her inhibitions to the side for her lol (the teasers for her have not eluded to more foreplay for now but hey maybe SuddenReals theory regarding Hunter scenes will be right but that hasnt turned out to be the case for the likes of the Aunt who is as far away from vaginal sex with Sterling as ever in all honesty despite Hunter enjoying it with her in a much earlier update). Catherines birthday week would be an unexpected update to bang Brenna though, theyre not after all leaving to go to the hotel this week and there will be plenty of people around at all times to give them little privacy (hence teasers)