I doubt Venus would play doubles, even if Serena wasn't injured, just because of her own injury.
As to saying the injury is healed after 2 months is not true. This type of injury, depending on how serious it is, can take several months, even a half a year, to heal. We don't know how serious it is, so, who is to judge when she'll be ready.
Good Luck: RENA, MATTEK, HAYNES, GULLICKSON, HARKLEROAD, RUBIN, GRANVILLE, LEE-WATERS, SCHNYDER, JACKSON, PERRY, KING, SUGIYAMA, PIERCE, TULYAGANOVA, IVANOVIC, KUZNETSOVA, MOLIK, DANIILIDOU, MEDINA GARRIGUES, PETROVA, PENNETTA, GOLOVIN, PEER, LI, SCHIAVONE, RAZZANO, ZVONAREVA, SPREM, SREBOTNIK, VINCI, & SAFINA